I carry both (but only in a bag on the way to/from the range). The poll was 3-.40 to 4-.45 and I had a chance to even it up, but I didn't--I went with the .45. My .40 is a PT740 which is super concealable, so if you're wanting more easily concealed, I'd go with a small .40. However, it sure packs a punch when you shoot it and my .45 (24/7 G2c) is a little easier on the hand. It's like many of the guys said above, go what works for you. The .45 is an American classic and won't ever be wrong!