The Calfee's definitely exhibit the Cannondale effect, i.e., not exactly an aero-optimized design. Even with the Rolf's, the Calfee has never been as fast on the downhills or flat-out when time-trialing as our Erickson was.

The Spinergy wheels, as others have noted, also aren't the most aero in the world; same story on the Topolino's.

But, the comfort qualities trump the aero handicap. I just stay in the draft if someone's able to descend faster.