There are few topics that will inspire a spittin' contest faster than:
- 9mm vs. .45 ACP; or
- Glock vs. 1911.
You're likely to get as many different opinions as you do responses. The .40 is a perfectly serviceable caliber, but I don't own one. I'm kind of partial to that big ol', slow .45 acp. If I were going to go down in caliber to increase capacity, I'd go ahead and drop down to a 9mm.
However, mine is a relatively uneducated opinion in this, as I have negligible trigger time with the .40. Take it for what it's worth.