Spinergy Rev X vs. Flashpoint 60. Which are more aero?

The Flashpoints should be faster. If you can find an older Tour test (the German bike magazine), they had data on the Zipps and Spinergys. The spinergy wheels were not very aero, from what I remember. They *look* aero, but the spokes really aren't, and the shape of the rim wasn't optimal either, having a sharp trailing edge rather than ovalized. The zipps, otoh, always test out near the top of the bunch, depending on rim depth.
You could also try www.rouesartisanales.com or www.biketechreview.com for more info on aero wheels.