I just used some of the Humbrol MetalCote paint. Specifically it was flat aluminum (haven't tried the other colors yet). I wasn't totally impressed with it for a couple of reasons:
- the 'grain' of the paint seemed fairly visible. Perhaps OK for larger scales, but mine was in 1/72 and seemed out of place
- it's fragile. Just touching the paint after plenty of dry time would leave residue on your fingers. The good thing was, the paint itself still looked pretty good. No visible fingerprints or anything. Just silver residue on my fingers. I tried to mask off a small section with tamiya tape, and although it didn't pull the paint right off, it did pull enough pigment off that it was noticeable. I tried to mask with parafilm, and had trouble getting it to stick at all. I didn't even try to apply decals over it, because I didn't think they'd stick at all.
I ended up putting a future coat overtop, then decals, then future, and then Testors Dull Lacquer. The end result was acceptable to me, but not what I was hoping for...
Here's an overall shot of the model, and another one that you can see the 'grain' in the finish on the wings (however, a 'grain' like that would probably be really good for some other things, like perhaps an aluminum block on a car engine??):