Interesting pistol, though I can't say I'd want one. It seems overly complicated to me, but then it is German. I have a P-08 Luger which amazes me with it's design. I think politics is the only reason that design didn't catch on.
However, Glock and my FN SCAR17S are simplistic in nature. The SCAR, especially. It's an incredible rifle that shoots very accurately and cleanly while remaining relatively cool.
As with most things German, such as BMW's and Mercedes, they tend to be over engineered, but quality products. I figure HK's are the same. And I assume the reason so many aren't available to the public, is because either they're classified as class III or they're limiting production to military or LE.
I do think they're overpriced to compete on the open market. The stars aligned for me to have purchased the SCAR. I doubt that will ever happen again. But I'm glad I own it. It took me months (nearly a year) to be able to buy additional mags. And I now have 5 and no more arms and legs.