My dad bought one in the 1980s, and when he got divorced, his (now ex)wife claimed it was stolen. There were no signs of a break in, and he's convinced she's still got it. Maybe she does, but it's reported as stolen if she ever gets caught with it...
But as for the gun itself, I was always very impressed with the accuracy, and from an engineering standpoint, I like how it has a relatively long barrel for such a short pistol (look how far back on the slide the ejection port is). But I never thought the grip was all that ergonomic; it's too blocky in profile. And it was a difficult gun to train with because it got so hot during firing. The only way to have a long, all day range session was to have more than one (not easy with such an expensive gun). An inevitable consequence of the gas retarded blow back system was the heat it transferred to the frame during shooting. H&K eventually added a plastic heat shield to the upper inside of the trigger guard, but it only did so much. So while I give it high marks for accuracy, reliability, and low felt recoil (thanks both to the gas retarded blow back and the low bore axis), it was doomed by its cost, its tendency to get uncomfortably hot, and the fact it was heavy for its size, especially compared to the polymer pistols that were the coming thing.