I just received a set of the Williams 58 carbon clinchers this week and raced them yesterday. I'm still a noob but I love them at speed. I can tell the weight difference when trying to get up to speed or on climbs, but once I hit about 19-20 mph I can feel the aero start to work and then around 24 mph they really start paying off.

I did a ton of research and the reviews of Keith's customer service (in addition to the wheel reviews) won me over. He promptly returned my call when I had questions about ordering. The wheels were in-stock and I had them in under a week. Happy customer here.

I would like to get a Powertap setup next year and psimet would be at the top of my list.