honestly I haven't shot or held a gen4, but the 2 is mighty fine. If it improves on the 2, then go for it. Let me know how it goes. If you are not leo, then summitgun often has good prices on new/unused gen 4 glocks. I like the fingergroove less models and don't need a rail. I like the smooth rounded edges of a gen 2 gun, and carried a 17 for a long while.