I'm a poor racer and I'm in the market for some high speed clincher tires for the early season tt's. the vittoria diamanté is marketed as a fast tire and it is also very light. It seems like such a better deal than the Corsa models for a person like me that is looking almost specifically for a fast straight line tire. Can anybody tell me if the diamanté is any slower than the Corsa models in a straight line? I suspect that the price jump for corsas is for handling and ride quality not necessarily rolling resistance.