Anyway RA developers are a little inflexible. Their dynamic rate system and not frame skipping dogmas have been given they a lot of headaches on android platform. Mame4droid runs smooth like butter on android with the sync code from mame devs. So shield is a good emulation platform independly of RA developing approach, which probabbly is fine for other platforms like iOs. My only complaint is sound latency but android devs are doing improvements.