I Ride A Cannondale R-1000 and LOVE it. I can tell you that the aluminum frame dose transfer a lot of road viberation to the rider, were steel may not. I just test road a trek 5.2 Madone (carbon fiber frame) and I though it fantastic bike. The carbon frame really soked up the rode vibs, I could see being able to ride longer distances with less fatigue on the 5.2. I still Love my R-1000.