So I bought one, XL blue.
It's growing on me. It's obviously neither as good as a street helmet on the street or a dirt helmet in the dirt. It is comfortable, suprisingly more quiet than I'd expected, and vents very well. It looks cool. The visor really doesn't catch much air at all.
The down sides are that the shield is slightly non-correct on the bottom and causes a bit of distortion. Look through the top and it is fine. This is understandable given the extreme curve of the helmet shield. There also is some glare from the sun, which borders on annoying as hell depending on where the sun is in the sky.