I've been using this Blackhawk CQC double-stack single mag carrier for about 2 weeks, and I really like it. The spring is tight enough to hold a fully-loaded Para Ord 14rd mag securely (you can't even shake it out if you hold it upside down), the belt clip is easy to put on and take off my belt but is VERY secure, and it looks good. It covers about 3.4 of the magazine, and doesn't allow my mag to wiggle,wobble,or move at all, but drawing the magazine is easy and smooth.
Maybe the double Mag carrier is a bad design, but the single mag carrier is a really fine bit of kit, IMO...
Anyway, I ordered 2 of these in Coyote Tan from Optics Planet, and they arrived yesterday. They look great on my belt with the tan Serpa, and I'm VERY happy.
So I've got this black one (Blackhawk part #410600PBK) and I don't really need it anymore. I've only had it two weeks, and have worn it about a dozen times. It's in nearly-new condition, and I have the original packaging.
The first $15 takes it. I'll cover shipping.