Unless you really need something tiny, I just don't get the point of this. As others have pointed out, you can get 2nd hand PCs for less, and they'll do a better job of things. ARM boards are great, and they certainly have their place, but they're far from ideal for emulator cabinets. Raw horsepower aside, most emulators have a lot more optimization behind them for the x86 architecture. The ARM ports are not nearly so refined, so both speed and accuracy suffer. After dropping several hundred bucks (at least) on a cabinet build, why cheap out on the brains?