NDD,
Belt mounted without kit is the Blade-tech. Hands down. Once you add kit things change. Vests or plate carriers obstruct the belt mounted pouch. For that reason I prefer to mount the pistol mag pouch to the vest when using a MOLLE system. Tactical Tailor or Eagle is at the top of the list. If at all possible piggy back the pistol and rifle emergency reload pouch. An example would be the DBT open top single M4 pouch with a pistol/ double pistol Eagle/ TT pouch attached to it. SO-Tech makes an integrated kydex, pistol/ rifle pouch. It is what I run on my kit. I've run it for 3 years and have yet to be disappointed.
Keep in mind all of this is from a guy that only does CQB via ground vehicle delivery. You start falling out of a perfectly good god damn airplanes I’m not responsible for where your shit ends up
Back to belt mounted with out kit: Whether you carry one or four pistol mags stick with the single mag pouches. Just get as many as you need. They conform to the body better than doubles and are far more concealable and comfortable.