I stumbled upon a nice full page review of the Gamebuino Classic in the first issue of the British magazine HackSpace.
"If you want something truly portable and are looking to concentrate on the coding side of things, the Gamebuino is the obvious choice; if you want to flex your soldering muscles, the Makerbuino is a better option at the cost of pocketability. In either case, you're unlikely to be disappointed."
Gamebuino: neat, quick to get started, and plenty of hacking potential - 5/5
Makerbuino: all the fun of the Gamebuino, but for DIYers - 5/5