I recently refinished a AR with Brownells Matte OD Green and it turned out awesome. I finished it off with Magpull handguards, Hoque Grips and a buttstock of who's origin I'm not sure off.
I got curious as to whether or not you could refinish the factory/USGI furniture, so I tried it.
Handgaurds, pistol grip and adjustable buttstock all took the coating and baked with no ill after effects. In fact the buttstock actually lost it's sloppiness.
Durability is the next question! I plan to use the rifle on a weekly basis on the farm, I should know by the end of the summer just how well they hold up.
I have since added a EoTech sight and replace the buttstock with the original Gunkote stock. I am really happy with the results of this working rifle.
It is a Bushmaster, 16 inch heavy barrel. (It's no longer evil, cause it's not a black rifle anymore)

Well, after some shooting done this morning, I noticed some of the gunkote flaking around the flash slots on the flash suppressor. It doesn't bother me, I want to see just how durable this stuff really is.

generally the thermal cure coatings are going to be much more durable that the air cure coatings.
expect the brownells to show wear. same with duracoat.

BTW: this thread will probably get moved to the refinishing subforum.