I've been on the roof of my 16SLK a few times. I watched a video put out by Jayco on how strong their roofs are over the competitors; they hold alot of weight before they sag. My dealer stated I could sit up there if I wanted to watch a spectator event if need be.
2015 Jayco Jay Featherlight SLX16XRB (TT)
2007 Ford F150 Tow Vehicle (TV)