powder coating is the way to go. I'm actually getting my frame done, along with the a-arms,swing-arm, motor, ..ect..
had it done once before, metallic blue …..silver flake with a transparent blue along with a clear coat..engine is silver flake with clear coat. Broke the frame …real bad!
Spray paint may be cost effective when touching up, (i agree), but powder coat looks so much better, is easier to clean, and it won't blow off like some spray paint when you power wash it. Powder coat also has a higher tolerance for resisting chemicals, (some spray paints will come off in the presence of brake fluid, gas, and oil, and some soaps, cleaners.)
Evenmore, powder coat is more durable than spray paint, and can flex with what its bonded to more than spray paint. it also absorbs impacts better than paints.
Powdercoatings bad side...when you chip it, it can crack and lose the bond to the metal. therefore letting moisture to get under the coat, and more often than not stay trapped there. In some cases it will rust under the coating and you won't be able to see it. Spray paint or traditional paint coatings tends to bubble when this happens. If you keep up touching up all the chips and dings there shouldn't be a problem.