Jwong & Trevor,
Thanks for the insights. I'm in the process of exploring this issue for a magazine article, and want to move up the learning curve a bit beyond my own experience.
Re ammo sensitivity, I have a Vektor CP-1 and a Heritage Stealth on their way, and will test both with a thousand rounds or so of various ammo. I'm curious if these inexpensive pistols will feed everything the way the P7 does.
Re care & maintenance, I'll also explore that. The P7 seems to work perfectly no matter how dirty it is, and anecdotes abound about thousands of rounds being put through the thing without any cleaning.
I have a theory that this design, especially in the case of HK, has simply been poorly marketed. The average shooter, if they've ever even heard of a P7, thinks it's an obscure PPK type design with an odd cocking mechanism. That this gun is easier to shoot with much less training seems virtually a secret. I raise an eyebrow when what is often called the best 9mm pistol in the world is only copied by a couple of relatively inexpensive South African originated designs. Not to take anything away from South Africa, but if it's that good, and if it apparently can be copied at fairly low cost, shouldn't Sig, Glock or any other major manufacturer come out with something fixed/gas retarded?
The market's greater familiarity with other designs may explain much, but the P7 type system seems enough of an improvement over competing defensive pistol designs as to justify more examples from more makers. I find it odd that that hasn't happened, neither in the States nor in Europe.