I'm not sure about the Burley Travoy, but my old Bell child trailer sits to the left of center. It is wider than 18" and, because it's to the left of center, tracks further out into the lane than would a center-tracking BOB. I'm not sure how Burley trailers track because I've never used one. My BAW 64A seems to track in the center. While it's an extremely good utility hauler, it would make a poor touring trailer due to it's weight (~35 pounds) and size.

My opinions...

If I wanted to haul large and/or heavy objects, BAW is the best option.

If I wanted to tour without trailer bound children and/or pets, the BOB is the best option.

If I wanted to tour with trailer bound children/child and/or pets, a child trailer is the best option.

If I wanted to tow a trailer off-road, the BOB is the best option.

It I wanted to grocery haul only and wanted to use a trailer, the BOB is the best option. Though, I happen to think panniers or a Yuba Mundo would be even better.

If I wanted to haul moderately bulky loads of around 100 pounds or less, a Burley is the best option.