I have run 300+ rounds of WWB 9mm through my PF9. I had 3 failures to feed where the nose of the round hung on the feed ramp, all within the first 100 rounds. After that, a little buff and a drop of synthetic blended metal conditioner (Mobil 1) at point of contact and no further problems. It will take a few mags full to get used to the thump! My first target looked like buckshot at 20 yards.
At 20 yards, and a little practice, the point of impact is about 6" above point of aim with mine and the rear site is drifted way right, but acceptable for what I need. Ran it through the State CCW course last weekend (3,7,15 yds) and kept them all in the 9-10 no problem. There are reports of problems with the trigger reset. You have to really let her go all the way back forward after firing or a short pull will cause the trigger to jam somehow, requiring an emergency manual slide operation, the ejection of a live round and fresh trigger pull to get back in action. While there are some fast shooters out there who can dance on the trigger at the reset point, I ain't one, and found that the snappy recoil forced me to let the trigger function as designed without problems.
Personal warning! I put one of the factory belt clips on the PF 9, similar to the one on my P3AT. Love it on the .380, tore my trigger finger up!!! on the 9mm. My now retired PF9 clip is for sale at half price if you just HAVE to have one.
Both are in the beauty shop now and I feel neked!
Mac.