I HAD a fullsize USP - loved the gun. Shot well. Loved to keep it cocked and locked. But, the grip was just too fat for me. From the front of the grip to the back, it's just rather long. It's not the width of the grip.
Anyway, I have small hands. I ended up selling it to pay for my last P99. But, it was a great gun.
Now the compact - I have a 9mm USPc - and I have wavered on keeping it on and off many times. I just posted another message stating that I have decided to keep it. Something about the compact - ya gotta really practice to NOT shoot low with it. Many people complain about this. But, the fullsize doesn't have this issue.
If U are looking at the fullsize and like it - get it.