I have had mine for like a year. They have worked great.
I just took a road trip hauling a small honda to Arizona and they worked great. I was in some major traffic jams in 95 to 100 degree heat and all stayed cool.
I averaged 14.5 mpg hauling the car and 21 mpg on the trip back with no load other then stuff in the bed. I also have underdrives, but I often can squeeze out 20 mpg in normal driving.
I purchased the troyer fans and have been very happy.
Sled...