I've finished several guns using DuraCoat. It's fairly easy to apply if you follow the directions. I use a Paasche DA airbrush and it works well. I haven't done any camo jobs yet but did pick up some digital camo templates to try out on a rainy day.
So far I've done a shortened Mossberg 500 and an AR-15 lower in matte black, a 1911 in OD green, a Spingfield SD40 in stainless, and numerous small parts. I'm going to try the "Urban MirageFlage" on a shorty AR.
My experience is that proper preparation is the key. I disassemble everything to the smallest component (big mistake with the MB trigger group, though) and degrease carefully. Brake cleaner works but may eat some plastics. I bought a sandblast cabinet on eBay for around $100 that does a great job.
My next project is to build a small, low-temp oven to cure the finish. My wife doesn't like it when I do it in the kitchen!

Oven curing isn't necessary, but it speeds the process up. One time I didn't like how a part turned out and had to blast the finish off. That stuff is tough! It didn't come off easily.