As others have said, my whole thing with H&K is that they are expensive for no good reason that I can think of, and with no real difference in performance over similar pistols of proven design. That doesn't mean I don't like them, and in fact I have always wanted to own a H&K of some sort, but the price tag has always kept me away.
I will say that the one exception, sort of, to this above is the P7. Having only limited range time with one, I can't intelligently discuss them, but I know what I like when I shoot it. I still can't afford one, but the design is unique and the function is superb. I really enjoy that pistol a great deal, but even used they were going for like $700-750 at my LGS, and thats just more than I am willing to pay for a used pistol.