its the american way to change something that is not broken. that being said I am one of those that has installed the apex kit in my 40c. I like it. I have felt the gritty feel go away and it is smooth like butter plus It did not take a thousand dollars plus in ammo to achieve this result. I agree that stock works just fine. Have you shot an M&P with the kit? there are slight differences but I think your right with a couple thousand round through stock parts they will get there eventually. Money wise I believe its cheaper to do the apex kit then the cost of ammo these days. good thought and wow you have had some fun with 15,000 rounds.