Solar Hot Water Vacuum Heater Experience?

Has anyone used or known of the vacuum solar hot water heaters where there is a hot water tank at the top of an array of vacuum tubes with a non-freezing fluid like this picture?
Experiences?
Pros?
Cons?

I have the opportunity to get some on salvage.

http://www.alibaba.com/product-detail/Sun-energy-integrated-pressurized-solar-water_1086140882/showimage.html

I have no experience with it but I *think* this is the type of solar hot water heater Geoff Lawton is going to install at his Jordan site in the near future. Are there other variations of a vacuum tube solar water heater? He said something about the system being very affordable especially when compared to traditional "panel on the roof, tank in the house" solar water heaters.