none exactly, just whats on the website. they look purdy, and looks like it'll get the job done. the way i see it, realistically, how often does the average person use at RTT? man, some of these things are pricey! and you always get what you pay for...but there's gotta be a middle ground for a best bang for your buck RTT. i like camping labs but autohomes overcamp is lookin very practical for what i plan for. cuz it's narrow, you can fit a cargo box (thule/yakima) next to it. did some measurements and an overcamp next to a 21" thule box would fit over 65" load bars from thule (2 sets for a total of 4 bars, maybe use 3 for the RTT/box), and maybe still have a gap in between for a high lift jack.
canada:
http://autohomecanada.com/file_gb/overcamp.html
usa:
http://www.autohomeus.com/rooftop/overcamp.php