My neighbor was asking for advice about the two bikes in the subject line. He is about 6'1 and about 175 lbs. So I think he will be riding a 58cm. He wanted to upgrade bikes and told me that he wanted something that would be available in town and he wanted a Carbon ride. He said he wanted something that would be racey enough to ride hard and fast with the local club rides but comfortable and stable enough to ride on centuries and in the mountains. I looked at both websites and recommended the Cannondale because I thought it would do everything he was asking for and most importantly be more comfortable for the long rides than the Felt because the Felt is a Monocoque frame. I know I would not buy a monocoque except for racing or short hard training rides because I am only 5'6" and I think the monocoque frame would fatigue me more than the Synapse. Is my logic correct or does it depend more on how the carbon is laid even if a monocoque or that since he is bigger, it might not effect him the same way as me? Just interested in your thoughts on this subject.