Another big fan here. Bought a 2nd-Gen (finger grooves, no rail) and couldn't get a good grip for squat. Did an even trade with a friend that had a Gen 1 and now have it on my "never, ever sell" list.
Positives: Very easy to control (and I don't *think* I have particularly large hands). *Very* accurate. Nice weight and balance which makes it point very well for me. Good magazine capacity. Reliable with everything I've run through it except for some unintentionally light handloads (note: 5.2 grains of VV350 is *not* the equivalent of 5.2 grains of WW231 - I don't care what anybody says).
Negatives: Nearly impossible for me to conceal on my frame without a coat on (actually due to height, not thickness). Pre-ban, full-cap mags are expensive as shit (we can speculate on the AWB expiration later). Umm... that's all I can think of.
I'm considering adding a G36 to the stable for warmer months (I'm currently recuperating from a minor case of "broke as hell", though) but, come winter weather, the G21 will be my carry gun.
Any specific concerns or questions on it, Dodgeram?