I bought a red Gameshell to playtest my Pico8 games on. I love it. High quality kit with solid directions and an active community. At some point I discovered that I could reskin the UI to look like a Teenage Engineering OP-1 and also play Sega Genesis games and now it lives permanently on my coffee table (proof: https://lewsid.com/gameshell.jpg). My only complaint would be the limited battery life.

The GameShell is obviously a polished premium product, much like the Teenage Engineering range. But when you compare what Odroid are offering with the Advanced Go for half the price it does seem excessive.