Thanks guys. It doesn't seem to me that I build particularly fast, but perhaps I do. I actually like seam filling, or at least I really like that first coat of primer when it finally looks like a whole rather than a bunch of parts. I build car models occasionally, so I use a polyester glazing putty (autobody product) for seam filling. It's a bit of a pain since you have to mix it with a hardener, but it dries in 10 minutes, it's very fine grained and it doesn't shrink at all. Sort of required to get a high gloss finish on a car model, but works good for flat finishes also.
I'm not sure I like the metallic lightweight paint. I'm afraid it will look toy-like on a small scale airplane. Not very intimidating.
Looking forward to seeing your versions.
Phil