Jen, same here. I can just "feel" my speed on the Slice. I see it too on my little speed-computer-gizmo. In a straight line I easily get 2-3 mph's faster than my roadie, even in the drops. BUT, I'm thinking about the Lake Castaic Oly in June. If I do it, I'll use my backup bike, which is an aluminum roadie with Zipp Aeros. Reason is that it's got some hills and lots of turns, which kind of negates the aero TT benefits. I think.