Seriously overpriced and inefficient. Ignore the things.
I remember looking at them when I first noticed them on NewEgg - and didn't even have to crunch the numbers, they're SO inefficient. They MIGHT be profitable if you have VERY cheap (5 cent or less / KWH) electric 'till the halving next year, but you'lll NEVER ROI the things unless your electric is free or bloody near to free.
I know it temping but not temping enough, i may buy one of the PI type controllers , it looks about the same as a PI2 for far less and works better from it says . i may buy one just to play with .