Finally decided to go with Kywi for my warbelt, at least I think.  Does anyone know of any other alternatives? I don't like the TACOs plus they are so expensive. The G Code Scorpions are ok but don't come in Multicam. What other open top mag pouches would you guys recommend.

Kywi is the way.  I’d wager even the Mandolorian uses them.

I had all taco's but disliked the hanging cord at the bottom. I tried kywi's and never looked back.

I tried other options, tacos, various pouches e magnets in em. Kywis are far and away my favorite for polymer mags

Mid height Kywi’s for the win

They put the mag at a great height and retain well without making them difficult to draw

Ive used about every mag pouch on the market, and esstac's stuff is definitely top of the list for me. Every belt/PC I have has esstac stuff on it.

I use esstac on my belt, but I ran Tactical Taylor pistol mag pouches overseas.  Loved them and they are the best of both worlds. They have adjustable/removable velcro flaps and they also have molded retention clips to securely hold your pistol mag in each pouch.

esstac

I hear how they are great for polymer magazines like Glock, but how are they with metal mags such as S&W or Beretta? Do they retain those just as well?

They work great on my metal FN mags

I have a double pistol kiwi on my belt and a triple mag kiwi placard on my PC. Great pouches.

For my belt mounted rifle mag, I use a Fireforce USMC speed reload pouch. They're dirt cheap, US made, and work extremely well for GI mags.

Something that will open up a whole world of options for you is that you can take anything kydex and wrap it in Multicam Adhesive fabric.  

It's very "tactical crafts" and if you're not a patient fella that can do that kind of thing it might not be for you.  It admittedly feels a bit ridiculous to use my wife's arts and crafts stuff to cut perfectly the fabric to apply it, but it looks pretty cool when you do it right and up's your "cool guy" factor since it's super custom.  There are some folks you can find on Instagram and Facebook who do custom wraps of kydex as well and will basically wrap anything you want to pay them to wrap in whatever camo pattern they can get ahold of.