I own a P7M10. It was/is my first gun that I shot and bought. My thoughts? It's the reason I started buying other guns. If you shoot 50 rounds through it relatively quickly (i.e. shoot off all 50 rounds in under 5 minutes, say), the thing gets really freakin' hot because of the gas-cylinder delayed blowback locking system. So I bought a .22 to shoot while it cooled down...and now I have 16 other guns.
As to the gun itself? The squeeze-cocking operation might've been strange, but as it was the first gun I ever shot, I didn't "know better" and now it feels just as natural to me as a Glock or a Beretta or a revolver. I'll admit that I've never actually practiced with it in self-defense practice, as I don't have a proper holster for it, and finding one is a PITA since no one seems to make one for the P7M10 (plenty of ones for the P7PSP and P7M8/M13). It's pretty freakin' accurate, with single-hole groups at 10 yards, unsupported, as the norm (and the gun has apparently been tested to shoot a 1.5" group at 50 yards from a machine rest). A lot of that has to do with the fixed barrel and the buttery-smooth trigger.
It does have the hold-open-on-last-round feature, and to release the slide you can either rack the slide, or you can loosen and squeeze the cocking lever. Takedown is somewhat of a PITA, since the barrel is fixed and the gas cylinder is attached to the slide (and the recoil spring in mine is still pretty darned strong, even after 16 years). With a little practice, I've gotten a bit better at breaking it down and putting it back together.
The drop-safety spring has broken twice on mine. It was $11 to replace the tiny spring each time from e-gunparts.com (plus their outrageous shipping fees). Magazines are also quite expensive, running about $100-apiece.
I don't shoot mine as much as I used to, since I have other guns that are cheaper to feed (I go through 5-600 rounds of .22LR a week...for about $14; 5-600 rounds of .40S&W is something like $150). I do shoot it every now and then, though, just to remind myself what a good, quality gun really feels like =)