My LBS is especially gracious during the off season. The sun came out Saturday, and I took their set of Madfibers around half of Lake Washington, over a lot of rolling hills, and through parts of some of my favorite rides. It was a nice day. This wasn't the first time I've been on the Mads, and they've also lent me an older (by a few years) set of Zipp 303s, and several others, all in tubular.

I felt like the Zipps were easier to turn at a particular speed, and my HR data backs that up. ( I don't have a power meter. ) I could feel a slight difference around 20 mph, and more at higher speeds. And I think I should have been able to get more speed going down some longer hills than I was able to on MFs.

Madfiber doesn't publish any useful data from actual wind tunnel testing. So I wonder if anybody in here has anything to throw even a little bit more light onto these wheels, and how they compare against Zipps and others in the same price and weight range? Impressions, especially backed up by power? Without a word on how, they claim their wheels are some of the best around when it comes to side winds - any thoughts on this? Finally, the MFs are 60 and 66 mm deep, but in a narrow V-shape; I think the older Zipps were 44 mm. Is it crazy to think the shallower rims could slice through the air better, and enough to feel it?

I'm leaning toward Zipp 303s, and assume a lot of this ^ is just marketing. But ... I want to get a second opinion.