I had a P11, and of the dozens of guns I've owned over the years it was the one I was most happy to be rid of. The trigger in particular was among the worst I've ever experienced. And I found it uncomfortable to shoot for any length of time, as a result of which I never got very good with it.
That said, my P3AT is among the best-value firearms I've ever owned, and the trigger is a joy (compared to the P11.) The trigger on the PF9 is supposed to be close to the P3AT's, which I would take as a big plus. And the thinness of the PF9 makes it sound like it would be much easier to conceal than the P11, while at the same time I've read that it is not particularly uncomfortable to shoot.
So Brian, I'd suggest you look hard at the PF9 if you're in the market for that size of 9mm, but steer away from the P11. If you need a short, fat, double stack plastic 9mm, save up for a Glock 26. Now that's a very nice gun for its size.