The camera has limitations, but I think it's pretty well made for the price. The uniqueness of the format increases it's value enormously too.
The lenses are definitely the weak point, but that's why the interchangeable lenses are brilliant! I've got the Russian lenses on order, and will probably sacrifice the plastic 90mm to recycle the lens mount for other lenses. Interchangeable lenses on a folder can you imagine? It makes you wish Fuji had taken that approach to the 667.
I wrote a fairly detailed review of the Belair on my blog: