PMAGs and DSG Aluminum with Tan Magpul followers. All in 30 rounders. Not sure where you heard that 30 round mags were unreliable. That's the first time I've ever heard that. However, I have heard of issues with 20 round PMAGs on several occasions. Never had any personal experience with them though.
Probably heard it from the same guy who says you should never load more than 25 rounds in a 30 round magazine, or from the guy who insists on tapping the mag on his head (helmet) prior to inserting it into the magazine well.
FWIW I'm all for 30 round USGI mags or 30 round PMAGs.