Another Synapse owner endorsement. I have the Synapse 3 with Ultegra, but I tried the 4 and really liked the idea of the SRAM shifters. Besides, the Synapse 4 comes in gorgeous white and navy blue. The SRAM Rival group set (2281g) will be a bit lighter than the Shimano Ultegra (2329g), so if you pair the Synapse 4 with some sweet wheels...The frame is the same as in the Synapse 3.