I'm looking for a duty magazine pouch for my single-stack 1911 mags. I'd prefer an open-top mag pouch, and I'd really prefer a quad-mag-pouch.  I bought the Blade-Tech quad mag pouch, and was not impressed with the quality. Does anybody have any suggestions or recommendations?

Uncle Mikes makes one (or at least used to).
There's a small company out here that makes a uniquely designed one.  AE Nelson Leather.

Both come w/ Flaps, so I don't know if they would really be up to the retention part.

I do own a customized one from nelson.  I was visiting their shop and they had this model on clearance.  It was special ordered, then then customer backed out.  IIRC the displays on their website are for horizontal models.  Mine is a vertical model/ flap on top.  The mags are held w/ the primer of the cartridge closest to you.  It's a bit tall, you'll see what I mean if you check them out.  If I was to wear something to this effect on duty, I'd have to wear it close to my radio.  It's just too tall for sitting with if you mount it near the buckle IMO.  I'm issued a Glock.  I'd rather have a 1911 or a SIG.

The mags in mine are ok as far as retention, but if you're looking at open duty carry w/out a flap, I just don't know if I'd trust it.  No tension screw,etc.  YMMV.
Since they're a smaller company, they may do something custom for you.

Good info. Thanks very much