I have a friend that is a superstrong rider (210-240 lbs). He rides a Giant carbon fiber frame. It's really lite and he says he feels the difference in acceleration compared to his Cannondale R2000. But like others say, CF isn't just about the lightness, it's about comfort too. Can't remember the model of his Giant but it was about 4k with Dura Ace 10 speed. Black and silver model,nice paint job!
FWIW, he has thrashed 2 sets of Mavic Ksyriums (one $800 set and one $1200 set with the red spoke) a couple of DA 10 speed cassettes and several chains in the last 3 years.
BUT, the frame is fine. I'd worry about the narrow cogs and chain durability with the 10 speed DA components myself. I ride 9 and hope to never go 10.
