Casco is just a terrible helmet. It's wicked hot (my Air Attack is practically air conditioned by comparison). It has very limited practical use, especially for a non-sprinter like me. It is overpriced. And some aspects of the build quality are quite suspect (I treat the visor attachment like it's made of tissue paper).
But I love it. 
Although the aerodynamic limitations of a sphere are well known, I don't think that is necessarily a disadvantage for short, chaotic efforts like match sprint and flying 200m, because:
Originally Posted by
Hida Yanra
Wind tunnel won't do much for sprint helmets as the head position changes too much to get "clean" data- too many things moving around.
Theo Bos during flying 200m:
In this position, I would guess* the Casco would compare favorably with just about anything. I suspect the Kask Bambino might be the best compromise... wish they weren't so expensive.
(*Of course, aerodynamics are notorious for often being counter-intuitive. And, unfortunately, the only extensive testing I've seen on helmets has been done in the stable tri/tt position. With the current trend of aero road helmets, hopefully that will change.)