The RS hasn't changed in like 3 years...it's dated.

Also look at the Defy Advanced. I recently rode the Roubaix SL3, Synapse and Defy Advanced and will be getting the Defy Advanced in the spring. LBS says they have sold a ton of Roubaixs but they are also having issues with the rear shifting...they believe due to the tight curve of the RD housing and where it exits the frame. They say the SRAM groups shift just fine but the Shimano groups have issues because Shimano's RD spring tension is lower than SRAM. I went into the test rides assuming I would walk out on the Synapse but I found it had a nasty rattle of the brake cable in the TT (internal routing) on chip seal pavement. I'm not dropping this kind of coin to have a bike that makes annoying noises.