Let me add some pictures of my experience with duracoat. Everyone always post pictures of guns right after they are coated, never what the results look like a couple years later.
You can find an album showing most of the application process at
Picasa Web Album. This was all anodized aluminum that was coated. Most of those pictures have explanations, along with a few pictures at the bottom of it immediately after being coated. It was degreased and then sprayed directly over the anodizing (per the instructions at
http://www.duracoat-firearm-finishes.com).
After using it every weekend for a couple months, the finish started to come off:
After a year of use (followed by a year in storage), a significant amount of the finish is gone. I haven't looked at this in almost a year, but it appears that the finish on the lower tube is actually shrinking and crinkling up:
For a "safe queen" the stuff would be fine, but for a carry/competition gun, I'd expect to be refinishing it often.