One of the most frequent questions I get while riding around is "How fast can you go?"
The world record for an hour ride on a trike is 70.68 Km. WWW.ihpv.org set by Pieter Pas out of Germany. Their trike is fully faired cygnushpv.blogspot.ca and not something I would be willing to ride on city streets.
I ride a catrike speed. A nice little aluminum frame trike, but no fairing.
How fast? Well I have had it up in the 70km/h range for a short distance while going down hill. My max on the flat would be about 50km/h mostly I am not concerned with going fast. I prefer just laying back and taking my time.
It is the ride that is important not the score. What ever bike you like to ride get out and ride.