I just painted my ERA and I'm in the process of color sanding and buffing. It took me quite a while only because I do everything to as close to perfection as I can - to the point of going back over it. and over it, and over it, and over it. Also I avoid power tools for body work and and thus I've sanded, and sanded, and sanded. There were a some areas that needed to be skimmed with filler to level or flush up adjacent panels - and I applied several coats of Slick Sand so I could sand some more. But the body itself is first class. When bonded to the frame it's so rigid it's like a vault. the only place that has any give is the rear fenders because I don't have the splash shields installed. I have a friend with a MK III FFR with the body still in gel coat and there really isn't much comparison, although I've heard the new MK IV bodys and pretty nice.
I have done a lot of sanding. From what I understand of the turn key paint jobs that ERA can set up, they sound like a bargain.