The AC unders just arrived. Gave em a once-over and pulled out the packer to see what it is. It's a convex piece of cloth textured foam, a little bit of a pain to get back in the pouch but it looks fine.
Perfect fit in the waist, little tight in the legs, bulges a lot more than what I had been using but not in an obscene way (looks much more natural). Very much worth the price, IMO.