I have a USP-.45 compact and a number of other .45's to compare it to (Sigs, SW 3rd generations, Beretta 8045, Witness, Springfields). The HK is accurate, reliable and easy to carry in the compact model. The full size is somewhat big to carry for many people. You pay more for the HK name than you do for other quality pistols. Customer service is often poor, as is the selection of aftermarket parts (presently there seems to be a shortage of .45 compact mags if you believe some folks at other forums). Mags are expensive- usually in the $40-50 range. The double action trigger pull is the worst of all my DA/SA pistols- long, heavy, and stacks severely before firing. The single action pull is average.
So while I think it is a quality pistol I think you can buy a similar quality pistol for less money with better customer support available. Good luck.
best wishes- oldandslow