I have a 6" KKM in mine and a Leupood Deltapoint on top. Put oversized controls on it for manipulation with thicker gloves. I just started hunting with it last year and didn't get a shot at anything because I only got to hunt one day of gun season in Ohio.
This year I plan to hunt the whole week and I'm sure Ill shoot something with it. I'm pretty accurate to ~45 yards now (4" group), as always I need more practice.
I'd suggest the Gen3 for the better recoil spring options without resorting to an adapter.