My brother in law and I had this conversation before Christmas. We decided that while we love our 1911's, We'd have to chose the 9mm, probably Sig 228. Ideally, I'd like for my wife and daughter to shoot the gun as well and, while I'm a big guy, they are not. Therefore, the .45 scares the hell out of them. Plus, when introducing friends to shooting, the 9mm is much more forgiving to new shooters. My P7 M13 is a little too big in the grip for most ladies but they really enjoy shooting the SIG. I try to introduce at least one person a month to the joys of handgun shooting. Further, while power is great, at 7 yards I can kill you as dead with one properly placed shot from my SIG as I can from my Springfield TRP.