I found that the trailer pulled very nicely behind our Cannondale T-1000 touring bikes .. I didn't feel like it added much wind resistance .. on the steep declines I remained vigilant about how the trailer was reacting to speed so I limited it to a top speed of 30mph .. I probably could have gone faster .. the trailer never gave me any indication it was going to be a problem at any speed
I have toured with a BOB Yak myself and I fully agree with your analysis. However there is something most trailer people never mention. Something which annoys me a lot and explains why I switched back to panniers again. When pulling a trailer, especially standing in the pedals going uphill, I feel a large dead mass behind me. A mass which tries to live its own life. I would describe it as inertia. The trailer gives me small sideways "counter forces" when pedaling and I don't like that. I guess these counter forces are a result of a non-perfect attachment system on the rear axle of the bike: There is a little play in that system. I believe that if the play could be fully removed, then the counter forces would be reduced. But not fully, because the entire trailer might flex along its longitudinal axis especially if you are hauling 60 pounds of gear.