Are you implying that those born and raised in areas that heavily regulate the 2nd have bad sense? I managed to leave NY, but I have the good sense to realize not everyone can. That was poor taste and a cheap jab, sir.
I think magazines made to full capacity dimensions but with limited capacity can cause hiccups. I don't know if that is the case with the Px4, but I have seen it with Glock handguns. Hopefully someone who has used the 10 round magazines can chime in with better info about their reliability.
-Cory