I'm of two minds on the finger grooves. On the one hand, the ones on the 19 fit my hand perfectly. On the other hand, I really don't need them for control on a 9mm. Do I wish that my old Gen2 G23 had them? Hell yes!
I agree. The finger groove models fit my hand and I never had a problem with them. That said, the new Gen 5 grips feels great as well.
There were little improvements in the finish, barrel, trigger and slide that were not earth shaking, but they are improvements none-the-less.
I will say the best handgun finish ever was the original Tennifer, on the early models. About 1/2 way through Gen 3 production is when I believe it went down hill. The Gen 4 finish is perhaps the worst. Hopefully, the Gen 5 finish will prove better.
