There might not be a single fastest wheel. From everything I've experienced and heard, wheels interact a lot with tires and forks -- probably your legs too. I wonder for example, how much a really narrow front wheel helps when the wind goes around and then just slaps into your whirling legs. Maybe you're better off with a wheel that acts more like a fairing.
That's why I would not trust tests that just stick an isolated wheel in a test rig. I also wouldn't trust tests that use a single tire across all wheels. A tire that works with one wheel might be trash on another. You gotta test the tire that each wheel mfgr thinks is best -- and then adjust for the rolling resistance.
The problem is the variability of a pedaling rider might overwhelm the differences between wheels. So IMO, the only answer is a whole lot of testing--preferably with the rider who's actually going to use the wheels. Clearly the guys at Hed, Zipp, and Specialized are all really smart and have a lot of experience. But I would particularly trust Xavier et al, because they do a lot of testing with real riders and different equipment.
To give an example of how complicated this is, I do Chung tests nearly every Saturday and Sunday a.m. when I don't have a race. I've tested the Hed Jet+9 and the Enve front against each other half a dozen times now. The Hed has been faster every time, except the last time, when I tried a different tire on the Enve (sorry, my secret and don't try to PM me for the answer). Go figure. Of course my tests are all at zero yaw, so results could differ......
BTW, the Roval tested real slow in field tests.
My latest book: "Out of the Melting Pot, Into the Fire" is on sale on
Amazon and at other online and
local booksellers