I have 2 different coatings on rifles right now. I have cerakote and Birdsongs Green-T. The cerakote is tough but has a tendency to "scuff up" for lack of a better term. The green-t is a Teflon based coating that is very smooth and looks great but I just got the rifle back a few weeks ago so I can't tell you anything about durability yet. The green-t should be durable though, it is applied by Birdsong for a lot of military and FBI firearms.
It wasn't difficult for me, my gunsmith and Birdsong are only about 15 miles apart. For those that aren't aware, Birdsong developed his coating himself and never sold his secret. His company is the only applicator. The only downside is that they do a lot of military and gov't contracts and they understandably put those at the front of the line. It took about 5 weeks for my rifle to be coated and I did have all metal coated. As soon as I mount my scope I will get some pics posted so you can check it out. It really is a good looking coating, I just hope it is durable!