I consider the .40 to be an answer to a question that didn't need to be asked. 10mm had a point, .40 not so much. anything a .40 can do defensive wise, a 9mm can do just as well, and in some cases better. with the right ammo. including permanent wound channels and all that stuff. Add the fact that 9mm is cheaper, easier to control (in my opinion), and not so prone to problems across multiple gun platforms (ie. Gklock KB's, broken Berettas and Sigs, etc). also in a free country you can hold more rounds, which when we travel to wonderful places for IPSC, we can use higher capacity mags than the .40 guys can.
how's that for a start?