Just had my first session with an 09 crazyfly bulldozer, 135x39. Absolutely amazing feel and ride. Previous boards include Slingshot Ignition and Slingshot SX. I've got to say that the stiffness of the carbon construction makes a very noticeable difference.
Conditions were 1 foot waves, 20gust25knots on a 10m Airush Vapor II 2009.
If you haven't demo'd or ridden a carbon board yet, I'd say it's worth the effort/money. Yeah, they are expensive. I'd rather have one of these than 2 of any other board.