Doesn't cowl induction generally work a lot better? Ram Air is pretty gimmicky IMO. Of course, any source of cool, fresh air is better than from the engine compartment.
The cowl is a very high pressure area, moreso than the grill area of most cars. It is also cleaner air, no bugs or road spray. On top of that, a cowl induction hood looks really cool.
That's all I got. 8)