I've had, and sold (Due strictly to financial reason.) three P-11's, and when I get in the position to buy another gun, a P-11 is at the very top of the list.
All three of them had the belt clip attachment for concealed carry, and nothing else. All three of them had over 1000 rounds each through them when I sold them, and I was very, very happy with them all.
One advantage to the p-11 that seems to have been lost is the fact that they can use S&W magazines for the 59, 69 series 9mm's. In my experience, the factory Smith 15 round mags worked with no modifications. I had two 15 round, and one 30 round Pro Mag that required that I extend the hole for the magazine catch just a bit for the catch to actually work. After that, they ran just fine. You get some interesting stares when you pop one of those 30 rounder's into that little gun at the range. :lol: