I use this to cut off the bottoms of existing trimwork while installing new hardwood floors that replace carpet.  The carpet runs up to the bottom of the door casings, and the hardwood is thicker, so you have to cut off the bottoms.  Rather than peel the things off the wall and reinstall them, just cut them in place with this guy.  You can do about 95% of them - all you need is enough room to pull the saw.  I had a couple trim jobs that needed a power tool, but that was only because I couldn't get the saw in and pull it because of space or obstacles.  Flip over a piece of the flooring to use as a guide, saw along the top, and you're ready to install.  The results look great - a custom fit.  This is about as fast and MUCH quieter than the power tool.