Not on the list above, but rode one day (Northwood to Cresco) on our Burley tandem and our son was with us on his red RANS Rocket. I do remember lots of 'bents, including some super fast carbon frames w/aero wheels, some 'bent tandems (both 2 wheel and trikes) and some sluggish BikeE's.
At one point, two bents were drafting our tandem and our son had a hard time getting around them until they figured out he was with us. I was surprised we were being drafted because we didn't keep that fast of a pace.
Here's a shot from the back of the tandem...
photo copyright 2005 by Holly