I finally picked up my 21 yesterday from my dealer, and have had a little time to familiarize myself with it. Over all fit and finish is excellent. I noticed right off that the slide seemed a little glossier that my 2nd. generation G-19. It has the ambi-mag release, and the 1913 Picatinny rail. I had Trijicon nightsights installed, and also purchased 2 additional mags. The SF (short frame) is indeed smaller in circumference the the original 21, and the reduced "hump" is quite noticeable. the feel in this respect is similar to the XD-45, albeit a bit blockier. One of my main gripes in the past with Glock, was the grip angle not being as natural as I would like. The SF has cured that problem, for me anyway. I shot it this morning to get a feel for the gun. The standard trigger pull of 5.5 was comfortable for me, and the short reset is a plus. My perception of felt recoil and muzzle rise seemed less that my XD. Re-acquisition of sight picture was quick and consistent. Another plus was that there was absolutely no movement of the gun in my hand but I'm sure that the finger grooves had a lot to do with that. I fired 26 rounds with no malfunctions and was shooting my favorite load of 200gr. SWC's. This bullet profile would not work at all in the XD, and was one of the reasons I sold the gun. All in all, I'm very satisfied with this pistol. A few 100 rounds will give me an idea of reliability, but then again...It's a Glock. P.S. Thanks, Ed... Pics... VillagePhotos-Free photo hosting, free image hosting, picture upload, free picture hosting, eBay selling tools, listing management, picture hosting and image management.