I am really vacillating between these two and can't make up my mind. One of the reasons is that I really like the white with blue of CAAD10 4. It also has better components. Costs $200 extra. CAAD10 5 comes in red and black, and I only like the black. Even though I told the shop to get me CAAD10 5, I am almost considering calling them tomorrow AM and asking them to change the order to the white Rival. I might have to wait longer since they're all out. If there are good technical/quality justifications, it would be easier to justify the switch, but color alone makes it irrational to pay $200 extra. In theory, some of the components are "better," but that's relative since both these bikes have quality components that should last.
One question I had: are there disadvantages to either of the colors? Does the white get dirtier sooner? On the other hand, since I am driving in dusty environments, wouldn't black actually show dust more readily?