I have the High Voltage model. There are threads about it on here (Here is my previous post about it: http://www.homebrewtalk.com/f39/one-stage-vs-two-stage-temp-controller-huh-206013/#post4222719
I really like it. I also have the STC-1000 and while it is nice and cheap and small, I prefer the Control Products one. I think that it is easier to use and program. You also have a lot more control over your temperature profile with the Control Products controller as it lets you set the temp range for both stages individually so you can adjust the amount of overlap. The STC-1000 is nice if you can't afford the extra cost, but I am really glad that my first temp controller purchase was the Control Products model.