The Hensley video is really pretty interesting to watch. There is a FWD Chrysler, Intrepid perhaps, pulling a 34' triple axle Airstream through a slalom course! Read that last sentence again! Not to mention other onroad antics like semi passing, and off shoulder driving.
Everyone that I've spoke with, and threads that I've come across over the years all speak VERY highly of the product. (Uh, and they also say it is pricy. )
But, man after you see that 34'r stay right in line in that video, it really gives the impression that emergency manuvers would be much more successfull than with conventional systems. That 2k could be the best money you ever spent.
As a side note, I have their McKesh mirrors, and have been very pleased with them.