I just painted my frame with one. Here is the good & the bad.
The Good...
Easy to use.
Covers a lot of area quickly.
Puts out a high volume of paint.
The Bad...
No pattern adjustment, so it is hard to direct to small areas. Had to touch up all the tight spaces with an air touch up gun. Used the round pattern nozzle for decent results.
It drips when held downward.
When nozzle gets clogged/overspray on it, it will squirt a big blob of paint out messing up your paint job. Clean it often.
Opinions....
If you just painted vertical surfaces, it would likely work pretty well. I would not suggest painting the hood with it unless you hang it vertically, or you will get drips in it.
Seems to work best if you spray continuously. Releasing the trigger at the end of each pass tends to clog the nozzle.
I suggest finding a pressure-pot style air type gun for best results. They will spray thick paint as it is forced out of the gun, only using the air to atomize it.
A gravity-feed style gun would be my second choice.