I like my PF-9, though I've only had it since April. Have fired about 300 rounds through it, most of which were my "duty" ammo (Federal 115gr JHP.) I cannot get the gun to malfunction. The gun now rides on my hip, between belt and pants ("ITB" carry) in an IWB holster.
The trigger pull is a little heavy, though you stop noticing this after several rounds, and would never notice it in a fight. It does require a full reset after each shot, meaning the trigger must be allowed to return fully forward. I thought this might be a problem on the range, but it hasn't been.
Some of the older PF-9s have a barrel feed ramp that has a greater incline then do the newer barrels, and this results in frequent jams when using longer rounds, such as 142gr JHPs.
The grip on the PF-9 is markedly thin, so much so that when the gun is lying on a table, it almost looks like a "real" gun that got run over by a steam roller. This thinness, combined with the light lower weight (the gun is "top-heavy"), makes the gun want to move in your hands when firing the first few times. However, the second time I took it to the range, I didn't even notice this anymore, so it must be something that is easy to get past.
For the money, it is going to be very hard to find a piece in this caliber that is as easily carried, shot, and concealed.