Hello darkhazuki !
I installed the Skelrom OS and followed this tutorial:
Still I had to buy microSD card, but I was planning on doing so anyway, because I needed space for games.
The only problem I seem to notice is the fact that everytime I boot it up, the device seems not to recognise the card, and I had to insert it again to make it working.
I may record how it performs, so far I've been playing PSP and PSX on it mostly. I can see that you are a Shenmue fan, but sadly I havent tried out Dreamcast emu, and even so I doubt the device could handle such complex game. Nonetheless it is a great console, still holding up.