Bikerjp - I see you have a CAAD9-4. I also have a CAAD9-4 (2010), although I have made a lot of changes. I also have a 2013 Supersix EVO Hi-Mod Red Racing. On the CAAD I am running Campagnolo Shamal Ulta 2-Way Fit wheels with Hutchinson Fusion 3 tubeless at 90 PSI front, 100 PSI rear. On the EVO I am running the stock Vision TC24 carbon tubular wheels with Veloflex Carbon tubulars at the same pressures. I have a Fizik Aliante Carbon saddle with carbon rails and Fizik Cyrano carbon seat post on both bikes. I find that they ride very similar. There is a touch more road vibration to be felt on the CAAD, but the difference isn't large. I feel the EVO turns in quicker than the CAAD. The biggest difference is acceleration; the EVO is simply much easier to get up to speed. Both are aggressive race bikes. Since you were originally looking at a new Synapse Carbon before you considered an EVO, IMHO you need to evaluate your priorities carefully. The new Synapse is reportedly much more "race" oriented than the previous version. I would try to ride both, back to back, if at all possible. They are both great bikes, but one thought that keeps coming back to me every time I ride the CAAD is what a great bike it still is.