I give this 4.5 stars instead of 5 mainly for the lack of automatic photostitch capability. (10/19/13 Update: Since this is basically identical to X6 and I gave that "4.5", it's only fair to "increase" this too.)

The interface for X5 looks identical to X4 but with a few more options here and there, so I don't have to relearn everything. One thing I was surprised about was after the initial install (I bought it the day Corel offered it for sale) when I went to close the program it said there was an update and installed Service Pack 1.

The package includes Creative_Collection, a separate 427MB installer file.  Corel's website says it adds dozens of new brushes, textures, and over 100 royalty-free backgrounds. I would say that if you are only retouching photos, you probably don't need to run Creative_Collection.

On startup, X5 displays Corel Guide. Two new tabs have been added, Learn and Do More.  Learn links to a handful of YouTube OVERVIEW videos ranging from under 2 to under 6 minutes each. There are no detailed tutorials in the Guide and no way to add links. I've found a LOT of tutorials on YouTube that are helpful and it would be nice to be able to link directly to them. Do More has links to download more Picture Frames, Brushes, etc., and links to Help for those. The Guide can be opened any time from the Help menu.

One feature not in X4 or X5 is photo-stitch capability, such as Photoshop Elements Panorama, that can take various overlapping images and AUTOMATICALLY combine them into a larger image. (Photo-stitch is not the same as X5's photo-blend.) I am mainly using X4 (now X5) to edit scans of old yearbooks, which often involves stitching together two letter-size pages (8-bit RGB 400 dpi) to 11x17 when an image crosses two pages.  I basically use Photoshop Elements for that, then open the PSD file with PaintShop Pro for the rest of the editing.

7/4/2013 UPDATE: I found a free application on SourceForge named Hugin Panorama used for photostitching, although I haven't tried it.

10/21/12 UPDATE: I previously said I could not manually photo stitch two 8.5x11x400dpi RGB images due to repeated crashing. I just found out the problem is I was running a multiple-clipboard utility called Spartan. Whenever I would copy something to the clipboard it was storing a copy. Apparently the utility was getting "clogged" due to the size of the files.  I just tried photo stitch without Spartan running and X5 doesn't crash.

A problem that first appeared for me in X4 and is also in X5 is I cannot scan more than one image without doing a save.  (8-bit RGB 400 dpi). When I do the second scan it crashes. [THIS IS PROBABLY ALSO DUE TO SPARTAN.] To scan multiple pages one after the other I have to use IrfanView. (IrfanView has a lot of nice auto-number features, so I'll probably keep using it.)

By the way, although I haven't tried it with X5, when I had both X3 and X4 installed I found that once I saved a file as type .pspimage from X4, X3 didn't recognize it as a valid .pspimage file anymore and wouldn't open it.  (Created in X3, opened and saved in X4, no longer X3 compatible.) I assume the same incompatibility exists between X3 and X5.  So if you need to save layers, etc., and switch between X5 and pre-X4 versions, save as a different file type such as Photoshop .psd.

Face recognition is new in X5. On a large set of images of the same person (several photo sets) it did a fairly good job of grouping them, but mainly where the angle, etc., of the face was pretty similar.

Like X4, there are three main sections, Manage, Adjust and Edit, and you can quickly switch between them with tabs in the middle of the Windows title bar. Adjust has a whole new set of Instant Effects with thumbnails showing the effect.  They range from corrective to artistic.

Something I and others have reported with X3 and X4 that I haven't seen in X5 is that when run it from the Start menu sometimes a message would appear that the program was damaged or illegally modified and needed to be reinstalled.  I have found that sometimes rebooting got rid of the problem.  Alternatively, the Start Menu entry is actually a shortcut. Double-clicking directly on the C:\Program Files\Corel\Corel PaintShop Pro X[whatever]\Corel PaintShop Pro.exe file would usually work. The program is NOT damaged or modified, the problem occurs with several versions of X3 and X4, and reinstalling does NOT fix the problem. But so far I haven't seen it in X5.

The difference between X4/X5 and Ultimate is Ultimate comes with several additional items in a Bonus Pack program. Two add-ons are Nik Color Efex Pro 3.0 over 250 effects and styles, along with 30+ emulated film types in 52 filters and over 200 additional Picture Tubes.  Picture Tubes are small images that can be "stamped" repeatedly onto a photo for artistic effect.  For instance, you might want to add a butterfly picture tube onto a meadow scene or a bubble picture tube or a star picture tube.

New in X5 Ultimate is the FaceFilter Studio 2 program from Reallusion. This is a completely separate program specifically for MINOR TOUCHUP of faces. The interface is pretty NON-intuitive--ALL icons, NO drop-downs or text-labelled buttons and no Help. It basically lets you change skin color, eye color, AND EXPRESSION. No change hair color, etc. In the Select Expression screen (Ctrl+4), if you click the button at the lower right next to Keep Result it shows thumbnails of the person with each expression applied. Click on a thumbnail and the After image will change. The altered expression can be exaggerated, so the Expression Strengh slider can be used to reduce the effect. The "Expression" can include things like changing the nose width (e.g., Elegant), not just lip and eye position. If you do a lot of portrait touch-up you'll probably want something like Portrait Professional instead.

The following is not specifically about X5 but may be useful: I used X5 to convert a PNG color scan of a yearbook black-and-white image to black and white using various techniques and these were the resulting file sizes. Chan means use Adjust => Color => Channel Mixer with output as monochrome. Sat-100 means set Saturation (Shift-H) to -100. 32k Chan means first decrease number of colors to 32k, then use Channel Mixer set as monochrome.

SOURCE FILE: 400dpi 24-bit RGB, PNG format. Scan of yearbook black and white homeroom photo.

1) Size: 52,141,230 Format: RGB 24-bit, LZW compression TIFF
2) Size: 42,102,300 Format: RGB 24-bit, 16.7 million colors PNG THIS IS THE SCAN.
3) Size: 30,496,028 Format: 64k colors, RGB
4) Size: 29,252,953 Format: 32k Chan, LZW compression TIFF
5) Size: 26,666,605 Format: 32k RGB
6) Size: 20,640,645 Format: 64k Sat-100 (Saturation to -100)
7) Size: 20,411,412 Format: Sat-100
8) Size: 20,330,961 Format: Chan (Channel Mixer set to monochrome) [SEE NOTE]
9) Size: 17,172,578 Format: 32k Sat-100
10) Size: 17,119,155 Format: 64k Chan interlaced
11) Size: 15,017,936 Format: 8-bit grayscale
12) Size: 13,032,349 Format: 32k Chan
13) Size: 13,032,349 Format: 64k Chan NON-interlaced

NOTE: Interestingly, when using Channel Mixer conversion to monochrome I wound up going from 121k colors reduced to 64k colors, but the actual Monochrome images only had 28-32 colors! And yet the images look the same as the grayscale, which have 256 colors.
I give this 4. 5 stars instead of 5 mainly for the lack of automatic photostitch capability. (10/19/13 Update: Since this is basically identical to X6 and I gave that "4. 5", it's only fair to "increase" this too. )

The interface for X5 looks identical to X4 but with a few more options here and there, so I don't have to relearn everything. One thing I was surprised about was after the initial install (I bought it the day Corel offered it for sale) when I went to close the program it said there was an update and installed Service Pack 1. The package includes Creative_Collection, a separate 427MB installer file. Corel's website says it adds dozens of new brushes, textures, and over 100 royalty-free backgrounds. I would say that if you are only retouching photos, you probably don't need to run Creative_Collection. On startup, X5 displays Corel Guide. Two new tabs have been added, Learn and Do More. Learn links to a handful of YouTube OVERVIEW videos ranging from under 2 to under 6 minutes each. There are no detailed tutorials in the Guide and no way to add links. I've found a LOT of tutorials on YouTube that are helpful and it would be nice to be able to link directly to them. Do More has links to download more Picture Frames, Brushes, etc. , and links to Help for those. The Guide can be opened any time from the Help menu. One feature not in X4 or X5 is photo-stitch capability, such as Photoshop Elements Panorama, that can take various overlapping images and AUTOMATICALLY combine them into a larger image. (Photo-stitch is not the same as X5's photo-blend. ) I am mainly using X4 (now X5) to edit scans of old yearbooks, which often involves stitching together two letter-size pages (8-bit RGB 400 dpi) to 11x17 when an image crosses two pages. I basically use Photoshop Elements for that, then open the PSD file with PaintShop Pro for the rest of the editing. 7/4/2013 UPDATE: I found a free application on SourceForge named Hugin Panorama used for photostitching, although I haven't tried it. 10/21/12 UPDATE: I previously said I could not manually photo stitch two 8. 5x11x400dpi RGB images due to repeated crashing. I just found out the problem is I was running a multiple-clipboard utility called Spartan. Whenever I would copy something to the clipboard it was storing a copy. Apparently the utility was getting "clogged" due to the size of the files. I just tried photo stitch without Spartan running and X5 doesn't crash. A problem that first appeared for me in X4 and is also in X5 is I cannot scan more than one image without doing a save. (8-bit RGB 400 dpi). When I do the second scan it crashes. [THIS IS PROBABLY ALSO DUE TO SPARTAN. ] To scan multiple pages one after the other I have to use IrfanView. (IrfanView has a lot of nice auto-number features, so I'll probably keep using it. )

By the way, although I haven't tried it with X5, when I had both X3 and X4 installed I found that once I saved a file as type. pspimage from X4, X3 didn't recognize it as a valid. pspimage file anymore and wouldn't open it. (Created in X3, opened and saved in X4, no longer X3 compatible. ) I assume the same incompatibility exists between X3 and X5. So if you need to save layers, etc. , and switch between X5 and pre-X4 versions, save as a different file type such as Photoshop. psd. Face recognition is new in X5. On a large set of images of the same person (several photo sets) it did a fairly good job of grouping them, but mainly where the angle, etc. , of the face was pretty similar. Like X4, there are three main sections, Manage, Adjust and Edit, and you can quickly switch between them with tabs in the middle of the Windows title bar. Adjust has a whole new set of Instant Effects with thumbnails showing the effect. They range from corrective to artistic. Something I and others have reported with X3 and X4 that I haven't seen in X5 is that when run it from the Start menu sometimes a message would appear that the program was damaged or illegally modified and needed to be reinstalled. I have found that sometimes rebooting got rid of the problem. Alternatively, the Start Menu entry is actually a shortcut. Double-clicking directly on the C:\Program Files\Corel\Corel PaintShop Pro X[whatever]\Corel PaintShop Pro. exe file would usually work. The program is NOT damaged or modified, the problem occurs with several versions of X3 and X4, and reinstalling does NOT fix the problem. But so far I haven't seen it in X5. The difference between X4/X5 and Ultimate is Ultimate comes with several additional items in a Bonus Pack program. Two add-ons are Nik Color Efex Pro 3. 0 over 250 effects and styles, along with 30+ emulated film types in 52 filters and over 200 additional Picture Tubes. Picture Tubes are small images that can be "stamped" repeatedly onto a photo for artistic effect. For instance, you might want to add a butterfly picture tube onto a meadow scene or a bubble picture tube or a star picture tube. New in X5 Ultimate is the FaceFilter Studio 2 program from Reallusion. This is a completely separate program specifically for MINOR TOUCHUP of faces. The interface is pretty NON-intuitive--ALL icons, NO drop-downs or text-labelled buttons and no Help. It basically lets you change skin color, eye color, AND EXPRESSION. No change hair color, etc. In the Select Expression screen (Ctrl+4), if you click the button at the lower right next to Keep Result it shows thumbnails of the person with each expression applied. Click on a thumbnail and the After image will change. The altered expression can be exaggerated, so the Expression Strengh slider can be used to reduce the effect. The "Expression" can include things like changing the nose width (e. g., Elegant), not just lip and eye position. If you do a lot of portrait touch-up you'll probably want something like Portrait Professional instead. The following is not specifically about X5 but may be useful: I used X5 to convert a PNG color scan of a yearbook black-and-white image to black and white using various techniques and these were the resulting file sizes. Chan means use Adjust => Color => Channel Mixer with output as monochrome. Sat-100 means set Saturation (Shift-H) to -100. 32k Chan means first decrease number of colors to 32k, then use Channel Mixer set as monochrome. SOURCE FILE: 400dpi 24-bit RGB, PNG format. Scan of yearbook black and white homeroom photo. 1) Size: 52,141,230 Format: RGB 24-bit, LZW compression TIFF
2) Size: 42,102,300 Format: RGB 24-bit, 16. 7 million colors PNG THIS IS THE SCAN. 3) Size: 30,496,028 Format: 64k colors, RGB
4) Size: 29,252,953 Format: 32k Chan, LZW compression TIFF
5) Size: 26,666,605 Format: 32k RGB
6) Size: 20,640,645 Format: 64k Sat-100 (Saturation to -100)
7) Size: 20,411,412 Format: Sat-100
8) Size: 20,330,961 Format: Chan (Channel Mixer set to monochrome) [SEE NOTE]
9) Size: 17,172,578 Format: 32k Sat-100
10) Size: 17,119,155 Format: 64k Chan interlaced
11) Size: 15,017,936 Format: 8-bit grayscale
12) Size: 13,032,349 Format: 32k Chan
13) Size: 13,032,349 Format: 64k Chan NON-interlaced

NOTE: Interestingly, when using Channel Mixer conversion to monochrome I wound up going from 121k colors reduced to 64k colors, but the actual Monochrome images only had 28-32 colors! And yet the images look the same as the grayscale, which have 256 colors.