My experience has been favorable with the Pearce finger extensions, and I have found the smooth ones tend to be more comfortable after a long shooting session. While the checkered ones are perfectly fine, they tend to irritate my finger after shooting for an extended time so I prefer the smooth ones. They are well made and I have never seen a fit or function issue by anyone who has used them. Hardest part about installation is getting the factory floorplates off, but once that's done, the rest is smooth sailing.