let me see what I can get you. One source that is based on power measurements on cranks can be found here:
http://kreuzotter.de/english/espeed.htm
If you compare fast diamond frame bikes with a lowracer the difference between Cw*A is 1.8 for the low racer versus 3 for the fastest diamond frame bikes. Adding a streamlined tail to the lowracer lowers the Cw*A to 1.5
another table that can be found on the site of M5 (I'm not sure if I can copy paste here due to copyright) shows a similar picture. Rhey claim to have measured at 250W: A carbon high racer (recumbent) will go 48,3km/h, a thriathlon bike 37km/h, a racingbike in racing position 35km/h, and a racingbike in normal position 32km/h.
And I completely agree these bikes are not meant for cities.