I'm not sure what the CAAD9 R1000 is in the US the CAAD9's are called optimo. If you have an 05 R1000 The CAAD9 ride is not much different than The CAAD8. If comfort is important then the Synapse Carbon is the way to go. for Racing, You certainly won't loose anything on climbs . Due to the longer wheel base you may drop some cornering speed But thats about it.It is too bad they only offer the SI BB on the top Synapse carbon model,the stiffness of the SI adds some response to the overall ride.