I tried this for our Cybermen in Doctor Who as an alternative to cold cast with polyester (
www.mfxreplicas.com www.millenniumfx.co.ok) but it didn't work. I was under the impression that the system would spray a smooth finish but instead it comes out spattered and requires a lot of hand finishing. All this did was kill all the detail on our fibreglass cast and take just as long to finish as it did a cold cast but the results didn't look as good and it cost a heck of a lot more.
I think it's fine for very large pieces, wall panels, shop displays, etc. but fine detail stuff and anything with a detailed surface it's really not suited to.
I also know that as a system it is very pricey but the technology isn't that unique. I already know of a coatings manufacturer in Europe who took one look at it and reproduced the aluminium version for a fraction of the cost. It's just basicaly cold cast polyester resin sprayed on to the surface. The basic deal is using the finest possible metal particle with tweaked spray equipment to get it to spray. For this you're paying stupid amounts of money.
Best
NG