I think it would work but I still believe the gear set up we use now is the most efficient. With belts you have to deal with tension, too loose and it skips teeth and slaps, too tight and it binds. Belts stretch and it's not as noticable as wear on a gear. On top of all that there is a lot more "stuff" spinning and moving increasing the total rotating mass. A belt is also prone to trapping debris between the belt and the cogs causing slippage and premature wear and it can just plain fly off if it gets something big enough under it. It's a cool concept but not the best idea if you want to go as fast as you can efficiently as you can.
