Will do. I might even have the one mag that was still giving me trouble exchanged for a new one, under warranty.
Tested for the extractor hangup as you mentioned, and when feeding really slowly the extractor still "grips" the round so I guess we're good as far as that goes. And don't worry, I respect the 4 rules religiously! I made a set of dummy rounds (spent case & primer, no powder) especially for testing things like this, I never keep live ammo anywhere near the weapon if not at the range.
We'll see how the gun keeps performing over the next few weeks. If I'm happy with it after another 2000 rounds or so I'll consider taking it to a match.
Thanks for the help everybody!