I just ordered the Retrax One for my truck. A buddy told me that Schlumberger has them on all of their company trucks and everybody really likes them. The covering is made of some high tech sounding stuff which is another word for Lexan. I've been in the marine industry for 15 years and have seen lexan stand up to some pretty harsh conditions, so I'm OK with it, especially for a $500 difference.

I loked at the others, but what impressed me about the Retrax is that it operates with one hand from the street side, can lock in any position on the rail, and doesn't require the use of a strap. We'll see how it works out.