I've had my 21 since '94 and I love it. I'm not trying to make your decision harder, but I gotta tell you... I recently bought a model 30 (compact version of the 21) and it's incredible! Much more concealable than my 21, and with the pearce grip mag extensions, it's every bit as comfortable. It still holds a full 10 rounds (with optional 9 rounders too) and if you really want to spend $100/each for pre-ban 13rd 21 mags, they will fit the 30 too - you can even get grip extensions that slip on the 21 mags like a sleeve and give you a full size grip as well. Here's the kicker - my 30 outshoots my 21!! On my last trip to the range, at 25yds, after going through 2 boxes (100rds) of 230gr FMJ, I had a 2" wide, 4" tall hole in the target centered horizontally, and slightly right of the center, but all between the X and the 8 ring, with only one "flyer" out in the 6. On my best day, I couldn't do that with my 21. The position of the group was a little to the right because my dealer installed trijicons needed a little nudge. Either way, you'll love it, but do yourself a favor and check out the 30 before you buy.
-John