Should you buy a ThermoBalance valve?
They are being discontinued for a new design. The ThermoBalance is a good valve, but the new one is going to be an improvement. It will also be more expensive. Look for the new ones to become available in 2010 and the old one to phase out by 2012.
The ThermoBalance was sold at Home Depot so you will have parts way down the road. They sold Hundreds of thousands since 2001, and are very good. If you are thinking of using ThermoBalance 3 you should opt for the current model, because it won't be all in one on the new models.