My tailwheel spring mount (the weldment between F-711 and F-712 that receives the tailwheel spring) came powder-coated from Van's. I'm glad it did.
Of all the areas in the plane that see moisture and grime, that last bay in the fuselage is the worst. The "mouse hole," the little hole you cut in the tailcone for the spring mount to poke through, obviously has to be a little bigger than the mount itself, and so there are small gaps around it. Any time you fly (or probably more accurately, taxi) in wet conditions, wet dirty sludge makes its way into (and out of) that bay little by little. Any oil vapors that end up on the belly also get in there a bit, and that attracts grime.
You could seal it off, I suppose, but I don't want to do that -- because any moisture that makes its way back there, i.e. rain that seeps down through the emp fairing and into the tailcone, well, it needs to get OUT somehow. So I haven't sealed that area.
Anyway, my point is that I'm personally half-ass at best with paint, and I'm happy to have the mount weldment powder coated and not have to worry about its exposure to the elements. It's not a part that I would want to have to remove for maintenance (i.e. treating for corrosion) on any sort of basis.
Had mine not come PC'd, I would have gotten it PC'd. Just my 2 cents.