We know they roll good thanks to Tom's testing:

Zipp Tangente SLSpeed 27C Tubular = .0028, 26W for pair @ 40kph, width = 26.8mm
Zipp Tangente Speed 25C Clincher = .0030, 28W for pair @ 40kph, width = 24.8mm
Zipp Tangente SLSpeed 24C Tubular = .0032, 29W for pair @ 40kph, width = 23.5mm
Schwalbe IronMan Tubular 22C = .0032, 30W for pair @ 40kph, width = 21.7mm
Zipp Tangente Speed 23C Clincher = .0033, 31W for pair @ 40kph, width = 23.8mm
Continental GP4000S 23C = .0034, 32W for pair @ 40kph, width = 24.8mm
Zipp Tangente Course 25C Clincher = .0035, 32W for pair @ 40kph, width = 24.7mm
Zipp Tangente Course 23C Clincher = .0035, 33W for pair @ 40kph, width = 23.8mm
Old Zipp Tangente 23C Tubular = .0045, 41W for pair @ 40kph, width = 22.4mm

I have a set of each and will be riding them as daily tires to see how durable they are.

Has anyone see any aero data on them?