Tacos are good. I have two and I’d still use them.
-PALS webbing one uses to mount them is TIGHT. Not a ding, really, but it takes some concerted effort to get them on with Malice clips. If you end up needing to move them, you’ll end up looking at your belt or vest/chest rig and sigh heavily.
-passive retention is good, but you may find one-handed insertions to be a pain in the berries once you get the shock cord tightened to the point that mags won’t move up and down when running/jumping/climbing on the jungle gym.
-great for off-size/shape items other than mags
Eagle FB are good, pretty much the industry standard for a passive retention pouch for a lot of years, the way I see it.
-taller than you want, though not significantly so. I still have a pair, though they’re on my alternate belt.
-the kydex box that works so well for retention is bulky, and you can’t stack other pouches, if that’s a concern.
-spendy, of course.
USGG. This gent has a double on his belt: https://www.m4carbine.net/showpost.php?p=860974&postcount=538
-not pricey, great retention, and you can stack.
-velcro mountings are a maybe/maybe-not.
Emdom IAP: http://prostores2.carrierzone.com/servlet/emdomusa/Detail?no=78
Currently 2 on my main belt setup, and my favorites.
-least pricey
-height-adjustable on whatever you mount them to
-retention so good it’s almost revolting
-singles only, no multiples
-can’t stack