I think you've already got a pretty clear answer going here, but just to throw another log on the fire...definitely Mec-Gar. I would only use ProMag in something that will absolutely never ever see any defensive use and that wouldn't bother me if it were to have a malfunction but I still feel like I need something other than just the factory magazine. Which is a pretty short list.

I have two Mec-Gar mags for my third gen and they have been flawless.