Only the .40s had some issues w/ the magazines - And, they were mags that were a bit older. I've read that people have had them replaced, and they had no real problems. Apparently, there was a flaw w/ the baseplates. It did not affect the 9mm.
As for my P99 - I seem to be famous around here for my opinion of that gun - it is my all time fav. I've had absolutely zero problems with either of my P99's or my SW99 I have. In fact, I eventually wanna get another P99 w/ the QA trigger to give that a try.
Why do I have 9mm - I have always prev stuck w/ that and .45 ACP - I am not into .40, nor any other rounds. I believe my needs are met w/ either of these rounds. But, I decided to stick w/ just 9mm for now, because the ammo is 1/2 the cost of .45 ACP. It was costing me too much to go shoot that .45 - so, at less than $5 a box of 50 9mm rounds, I can afford to go every other week to the range