The deal is that the Mil-Spec finish (molybdenum-based dry-film lubricant) isn't all that great as a mag finish, primarily because it wears off quickly.
Teflon finishes are NOT Mil-Spec, but are newer and much superior technology. It is far tougher, it's nice and slick so your ammo feeds well, and tends to shed dirt easier.
The main reason the military doesn't use it is because it costs a lot of money to certify any change, and they don't feel the need to change (what to them is) an expendable product that they can get all the replacements they need.
As is often the case, what's available to civilians is better than what's used in the military.
Unfortunately, La Belle Industries, the USGI mag contractor that produced these teflon-finished mags for the civilian market, hasn't existed for about 5 years, so even with the AW ban ending, there may never be any more factory teflon-finished mags.
-Troy