Most quality products rate at something around 4.5 stars - IMO this is a 5 Star product.  For years I have used shop made wooden inserts, but when I bought a new table saw I decided to try ready made inserts.  These Leecraft inserts have made a believer out of me.  With the two adjustment screws and tabs, they fit my Dewalt DW 744 precisely and snugly.  Add to that the nice finger size hole in the insert, and you have an insert that fits right and is easy to swap in and out.  True, you can't use them with the rive knife, but I don't use it anyway.  I bought 2 to begin with, one for a thin kerf blade and one for dado use.  Now that I see how well they work, I'll buy more for all the common dado widths I use.  On most products I find myself thinking "if only they would have..."  Can't think of anything I wish they had done on these inserts - simply put, "Buy it, you'll like it!"  Makes me wonder why Dewalt doesn't offer a comparable, but if they did that, then they would have to offer a decent miter - not going to happen!