I like them a lot.
My .40 USP is very accurate for a service pistol. It seems to have less felt recoil than my Glock 22.
I am not crazy about double action triggers, I like DAO or SAO myself but the USP isn't bad. I would say it is just as good as my P226.
Stopping power: The power some guns have to make you stop what you are doing and get your wallet out.