Amazon has some reviews for the non-rs racks. Some people love them, others hate them. A few people seem to have trouble keeping them on tight, but I don't know if it's a problem with how they're installed or due to a common problem on the tightening mechanism.

http://www.amazon.com/Rhino-Rack-2500-Series-Aero/dp/B00KL7O152

Maybe have a look at Thule.