Do NOT buy the Mercury wheels!
Before I purchased my first set of Flo Wheels I was looking at the Mercury's. I subsequently did not buy them but two friends of mine one of which is on slowtwitch here purchased sets and both no longer have them due to the wheels overheating during long down Hills. Both of them dealt with wheels developing large bulges in the carbon around the brake track both are very lucky they did not have blowouts.

I will second this, i purchased a pair of their aluminum box rim wheels for training and they have been a nightmare. The build quality was terrible and i ended up completely rebuilding the wheels. Another friend purchased their CC's and had build quality issues and the brake track had heating issues. You are better off buying direct from far sports or yoleo if you are wanting cheap carbon clinchers.

Can't go wrong with Flo or He'd.
Flo customer service is great!

I was looking very hard at those for a long time. CompetitiveCyclist has had a killer deal for a while. Recently I rode with some cyclists from a team who all had them. I assume they are sponsored but didn't ask. Anyway they couldn't stop raving about them. You could say they did because they were (might have been) sponsored but this seemed a bit over the top for somebody just talking to another cyclist on a ride.

Anyway I ended up going with a different brand.