If you don't have any experience with 40SW you probably should stick with 9mm. I have had no problems with my Shield 40. I also have a 40c, but most often carry the Shield because it just carries so well. However, one thing wrong with the "buy all your guns in the same caliber" theory is the situation most of us seem to be in right now. I've had very little luck finding any 9mm lately, but I can still manage to find 40SW or 45ACP fairly often. I like to shoot different calibers. If all I had was a 9mm, I'd be spending a lot less time at the range! IMO, the 40SW round is not all that snappy. Nowhere near as soft a shot as a 9mm, but easily controlled.
