I also owns the 21 c, 30 and 36 models. I absolutely love them. Very accurate and soft recoiling. My first Glock was the 21, a long time ago, and i sold it in a trade for the Walther P-99. A real loss. I could buy now a 21 C, that's another experience. When i shoot the 30 i really wonder why i bought the 21 C, because the recoil is really minimal. But also loves the 21 C. At last, real good guns. In my opinion better than any other Glocks except maybe the 17 and 19.
Only fault, at least for myself, is that the 21 is a bit big for concealed carry.
Only fault, at least for myself, is that the 21 is a bit big for concealed carry.