I prev had a fullsize 9mm USP, but the grip was rather large for my hands. I have a USPc 9mm, and I have about 3000 rounds thru it now.
When I first got it - It shot low. I swore it was the gun, until I rested it on sandbags, and I saw that the sights were spot on. It took about 800 rounds before I stopped shooting low with it. It was fun to go to the range each time and make progress with it.
Everyone else that shoots it also puts the rounds low when they first try it.Something weird about the design - it is real easy to end up slightly moving the gun downwards as that trigger gets pulled.
Anyway - if your aim is a little off - just keep at it.
I just put my 1,000th round through my USPc 40 yesterday. Not a big deal compared to others out there, but a nice little milestone for the pistol. Not sure I even need to say this, but 100% reliable so far.