The Mavic is not in the same class as the Dura Ace. The Dura Ace's hubs are better - especially the rear hub- and the Mavic does not have structural carbon, just fairing.

I'll pick the Dura Ace C50 clinchers over the Mavic Cosmic Carbone any day.

YMMV.

And at $990 for the Shimanos, that is an effing great price. The cheapest I have seen them is about $1200.

Could you be kind enough to PM me where you found that price? Thanks