I'm getting ready for my first weekend trip with my teenager son. Problem is that we own 2 road bikes with no rack eyelets. Mine is a Fuji Gran Fond carbon frame that will take up to 28c tires and his a Trek Madone 2.1 that will take up to 25c tires.

A friend suggested a cargo trailer that attaches either to the seat post or the quick release on the rear wheel.
I've been window shopping the burley trailer with 2 wheels and the BOB Yak with one rear wheel. They are both very price and I've seen several cheaper brands at amazon and other online sellers.

Is there any advantage/disavantages for the 2wheel trailer versus the one wheel trailers out there? I'd assume the 2 wheeled ones would be more stable and the one wheeled would be more nimble/maneuverable but I'm just speculating.
What say you?