You know, although I generally really like H&K products, but I just have never warmed up to the USP model. I have handled them at many of the gun shows, but there is just some kind of body language between my hand and the gun that sends me the wrong signals. I can't put my finger on what it is, whether it is pointability, balance, bulk, whatever, I just have never had the desire to buy one at all.
And as for the Glocks, I had a model 17 and just didn't like it at all. I was glad to get rid of it when I finally traded it off at a gun show a while back.
So if I had a gun pointed to my head and forced to choose between one or the other, I would have to go with a USP in the hopes that it would eventually grow on me after I had it for a while. I bought the Glock thinking I would like it, and didn't, so I know there is no chance of it growing on me if I got another one.