I don't have a PF9, but I have a P11 (my 3rd), and a P3AT (my 2nd).
Both these are flawless.
When the P11 came out, many of them had problems, which the factory address or refunded. After the first year or two the chances of getting a problem child became pretty remote. The last two of mine have been flawless.
Same with the P3AT. Both mine have been 2nd gen, and have never failed.
Personally, I decided to stick with my P11 a while longer.
the P3AT is my daily carry. Both are in the chrome over navy blue colors, which I like a lot. Maybe by the time the PF9 comes out in Chrome/blue it will have the kinks worked out.
And then there's that 2nd strike capability. The P11 and P3AT have it, but the PF9 doesn't, as I understand it.