Funny, not many on this thread have endorsed the .40 but I had a few and enjoyed the caliber. I had a few Glock 10MM and would prefer them but the additional ammo load in the mags for the .40s is something to think of. And I'm sure .40 or 9mm is a LOT cheaper than 10mm right now.
The USP is a remarkable handgun, though outdated in some ways, but it is the only handgun I know of that was designed from its inception around the .40 S&W, and not one adapted to it from another caliber.
As I said in another post, there used to be, fairly recently, LE USP 40s available for around $350, but those seemed to have disappeared.