I am riding an Aethos and have but about 250-300 miles on it so far. I think the ride is great. The Aethos has the same geometry as the SL7, but obviously in not an aero bike. From what I understand the stiffness is between SL7 and the Roubaix. The bike is very responsive when I put the power in to it and when cornering. I do not race so having an aero bike was not as important as having a bike that was light. As everyone has said, ride each on and get the one that feels the best to you.