I think that 9mm has always been cool, the 40 is a great round but your giving up capacity of a round or two for the same size weapon. When it comes down to it a 147gr hollow point will get the job done, there have been studies to prove it, and it is all about shot placement. I love my 45 ACP but a 9mm will get the job done, now when the R45 comes out, I will be getting one carry piece.