The bed door leaking when closed is the most common problem.
If you can, try to examine it immediately after a good rain and before the owner has had a chance to dry it off.
The delamination tends to happen with the leaking as the water sits in the bottom of the wall frame and wicks up into the bed door core and it delaminates.
If you can find one that doesn't have the leak problem then they are a fantastic trailer.
I think 2022 may have been the year that they switched to the new permanently attached canvas. The initial design had a leak problem that was less frequent after a design change. On the new design, check that the black seals are not separated at the top corners.
2011 Rockwood Signature Ultra Lite 8293SS, 12K Equal-i-zer
2016 Ford F-250 XLT SuperCrew, 6.2L, 4x4, 6'9" bed, 3.73
2010 Rockwood Roo 23SS (2012 - 2014)
2009 Ford F-150 XLT SuperCrew, 5.4L, 4x4, 5'6" bed (2012 - 2016)