I use to own a Glock 27, 40 SW has a very sharp recoil compared to other calibers and in a plastic gun with a short grip it is really hard to shoot quickly and is quite a hand full.

Personally, I think the best CCW handguns are slim, short grips help concealing but not much and short barrels I think don't make much of a difference. So I prefer Kahr arms pistols for CCW, they are very slim, and the trigger is very good.