I have had a Sherpa Crestone for just over a year. After I finished mounting it, one side panel ran a little too close to the roofline, but when I contacted Sherpa, Will was quick to respond and sent some replacement mounting brackets - the new design - and it fits perfectly now. It's as modular as an erector set and quite easy to add accessory brackets and such exactly where you want them. Very solid and no leaks. Little to no wind noise (I'm a little deaf, but my wife isn't and she has no complaints).
I was a little skeptical from the engineering perspective: The brackets are bolted to the roof through the rubber mounts. The horizontal crossbar rides on a pair of those brackets, held by a few 1/4" bolts. The long side panel is bolted to the crossbar by two 1/4" bolts on each side. The next crossbar is bolted to the side panel by two 1/4" bolts. So any weight on the second crossbar is distributed through quite a few bolts along the way back to the first crossbar and the mounting feet. A cheap copy would flex, separate, and fall apart under stress. This is not a cheap copy. It feels solid, and rides quiet, with no creaks. I run a Gazelle tent, a tailgater awning, and four traction boards on the roof. Maybe a Gobi would offer a more integrated construction, but with less modularity, more weight, and rust.
