Anthony,
I definatly agree that the Goldberg Cub is tuff. It is built like a masonry outhouse, although it is a little heavy. Seems like it would go together easily and the website seems to indicate that they are now laser cut. I don't know about the 1/5 scale Sig one, but the 1/6 scale cub of theirs requires a little skill and patience to put together. The new 1/5 scale one looks like it would be a little easier. It also looks a lot better than the Goldberg one, IMHO. Don't discount Sig's lighter construction as weaker, though. Mine has had some pretty bad ecnounters with the ground and has faired well.
Ben