I personally prefer compact/mid size pistols for ccw. Many people successfully carry full size pistols. More power to 'em. I find the compacts to be a lot more comfortable and for me they stay concealed better when I'm sitting down.
I've tried carrying a full size USP and it didn't work for me. I prefer to carry the USP Compact or Glock 23. I'm about 5'9 / 220 -- a lot of this is going to depend on your body shape / size.
It's not really about the girth, it's about the length for me (yeah yeah, gay jokes, etc.) The longer ones stick down further and make sitting uncomfortable, and they make my draw slower because I have to get the longer slide to clear the holster (more pulling "up" as part of my draw.)
If I was you, I'd try carrying it and see how it works for you. You may love it.