H&K was "out of the box" (and sometimes still is) for several years.
The VP70Z/M had one of the worst triggers, in one of the most advanced handguns ever made... the first polymer framed handgun, which predated Glock by over 10 years.
The P9, in addition to using a roller locking mechanism similar to the G3 rifle has, and in particular the P9S Target/Match model, on of the most beautifully crisp and light single action trigger pulls ever in a production gun.
The original P7 PSP, P7K3, M8, M10 and M13 were equipped with all of H&Ks "eggs in one basket" so to speak. The prototype .45ACP P7M7, of which there were, arguably, only 6-7 made, had a unique hydraulic slide buffer. P7 lovers would, literally, kill for one of these guns.
The P7K3 had the bonus of caliber interchangeability in .22, .32ACP and .380ACP and a (simpler than the M7) hydraulic slide buffer in place of the gas-retarding piston of the larger, production guns.
- All 9mm and .40 Auto P7 models have a gas delayed blowback, fluted chamber, fixed-barrel operating system that was self-compensating for variations in breach pressure between target, standard and +p ammunition. This system was so effective that, upon firing, the gun would eject empty cases even if you removed the extractor from the gun.
- At the time, the P7 had the lowest bore center relative to hand position of any gun made. Very quick to get back on target.
- A totally unique safety system in that if the cocking shell, pivoting from the bottom of the frontstrap, was not depressed, the gun could not fire.
- The cocking shell required approximately 14 lbs to depress, yet once depressed, only 2 lbs of pressure required to hold it in it's cocked position.
- The cocking shell, upon being depressed, set the striker in a firing position, and only required a short, light and smooth pull of the trigger to fire the gun. Upon firing, as long as the cocking shell remained depressed, the gun would reset the striker to the firing position. Once the cocking shell was released, the striker was "de-cocked" and the gun rendered safe.
- An interesting fact. You could fire the gun by pulling the trigger first... then pulling the cocking shell. As the cocking shell made a little "clicking noise" as it went over center, many thought this was a design feature to allow someone to shoot without making any noise first... and giving away ones position. I think this was simply a unintended function of the design.
- The barrel was hammer forged, polygonal rifled and had no taper, runout or variation to .0001".
- P7M models had a ambidextrous, press down to operate magazine release.
- When you changed the magazine on a P7 with the slide locked back, depressing the cocking shell would not only set the striker to a firing position, but release the slide as well! One of the fastest natural magazine changes on the planet, and one of the many reasons why gunsmith Bruce Grey worked diligently to create P7M8 and M13 competition guns.
I've owned a VP70Z, a P9s 45 Target, a blue K3, a rare factory nickel M8 and a less rare nickel M13. I never bought a M10 because H&K added weight and height to the slide in an effort to control slide speeds. The hydraulic buffer of the M7 was too costly (according to H&K pundits). This was, arguably, the worst of the P7 series and quite unpopular at the time. Now of course, because even though it's a bit of a pig, it's still a P7, so it's stature as a collector piece is secure.
I sold my entire H&K collection when I developed colon cancer... I should be sad, but as I sold them all for 2-3 times what I paid for them, and I'm still alive, I'm not that sad.