Don,
I powder coat mine, the durability is what I'm after. The problem I have had is what has already been talked about, that is the slight orange peel texture it sometimes gets. If you ever look at one of my trailers there is hardly any. So, the conclusion is it depends a lot on who is doing it. Believe me it makes a huge difference.
The other issue for me is the paint matching the body color. (black is not always black)My solution for that is I color sand the powder coating then spray the same color as the body on all the areas that are seen while standing up next to it. So I get the durability underneath and the flat, shinning, matching color where you see it.
Ken
If you send me your frame I will get it painted for you, It will be flat and shinny