I own (or have owned) almost every brand of polymer handgun out there. This includes everything from a couple Glocks, a couple XDs, to H&K.
My H&K USPc .40 is by far the best shooting, most reliable, most accurate, and overall my favorite polymer gun that I've ever owned. There is no hype with H&K, despite what some people might think. The entire design is well thought out, and the manufacturing process doesn't include any shortcuts. Everything from the robust design, perfect tolerances, and even control placement is perfect IMO.
I also have never had a gun that feeds every type of ammo so smoothly. Even when it's dirty, it feeds anything without a hiccup. Now, you shouldn't make a habit out of it, but if you guide the slide forward and chamber a round slowly the USPc will feed any type of round so much smoother than any of my other guns, including my Glock 19 with FMJ ammo. Shooting it is the same story. Flawless, solid performance.. You can just tell from how it recoils that H&K knows how to build handguns. Maybe it's the built-in recoil buffer system H&K uses? I'm not sure. But I find that shooting .40s&w from my H&K is more pleasant than shooting 9mm from some of my other guns.
Some people hate on H&K because of the premium price, but the price is easily worth paying for what you get.
To be fair, if there is ONE complaint I have with H&K it is the factory SA trigger pull. Don't get me wrong. It is much better than a factory Glock, XD, or M&P trigger pull for example, but it isn't as crisp as a Sig or finely tuned 1911 trigger. However, a trigger job can be performed to make the trigger much better. Other than that, and the rather beefy slide (but it's beefy for a reason), H&K really offers you a gun with "no comprimise." Definitely go with H&K. You won't regret it.