I've got a USP 9mm, had it for 5 years. Must be around 7500 rounds trought it, it never jammed, never failed and still look brand new.
frankly, I don't think I can ever let it go; everytime I think I could I just pick it up and change my mind. Some say the price is not worth it, but personally just looking at it reminds me why it is more expensive than say the M&P I carry at work. You can feel the difference just handling the thing, not to mention when you shoot it. There is no way I can shoot as good with the M&P, and even tho I fired maybe 1500 rounds with the M&P, I got more failure than I like out of it.
The only thing I'd recommend for the USP is to handle one before you buy. The blocky grip And/or the mag release are not for everybody, it works perfect for me and my medium hands but it is not the most ergonomic grip out there. I personally prefer the mag release than the push button type as I never change my grip using my middle finger.
So my USP is a DA/SA with safety/de-cocker, lever/paddle mag release, double stacked, polymer framed, aggressively stippled, polygonal rifled barrel, recoil reduced... You get the idea. There is nothing like it out there.
The only thing that sucks is that I cannot get a 9mm USP compact, but I'll get me a 45CT eventually.