Ok so quick update because i got the units today.
I want to do a proper write up after spending a little more time with it so this will be short.
Firstly, assembly was simple, easy, fun, quick.
Firmware flash and update was less painless than any phone ive ever flashed. About 15 minutes to download all the new binaries and reinterpret the (slightly) out of date guide.
It worked first time.
Emulation is great:
Games tested: 3
All ran perfectly, controls were tight and everything felt right.
Games tested: 4
All perfect, full speed, 60fps, no graphical glitches, very happy.
Only tested Mario Tennis
There seems to be a flashing issue on this build of the emulator (or this rom) that's affecting the Black Layer on this game, also theres a fair bit of frame skip enabled.
Played two matches and the controls were perfect, certainly very playable, and not that distracting, need to log the issue because ive seen video of others playing this game without my GFX problems.
Only tested Wario Land so far
It played perfectly.
Only tested Super Mario Bros. so far
It plays really well (better than virtual console on 3DS) had an issue with backwards jumping but i think its because im used to less play in the controls (these are aftermarket GBC buttons in the odroid-go and they travel more than the NES or 3DS for instance)