Empirical unbiased testing has shown that the most you can hope to gain is about 0.3 mph with very deep section aero wheels. Several years ago Bicycling magazine conducted downhill coasting tests comparing several aerodynamic wheels with a conventional wheel an the results were in the 0.1 - 0.4 mph gain.
Uphill tests would, of course, favor lighter weight wheels but it would be hard to eliminate the differences in riders.

Al