I found it difficult to set up (confusing instructions). Very compact and went in nicely. I know of nothing better. It is a bit pricy but considering the alternatives?
I sugget you get themanifolds that attach to it. I also had to supervise it with a zone valve in series. If there is any pressure in your system between the high side of the boiler and the low side it will feed through the mixing block and not be able to control the heat. Remember you don't want the floor to go above about 102 ever. My floor run around 80 to 85 which is just lovely. (I live in Alaska).
Watch out for the Manual/automatic switch. It is very poorly defined (no labeling and didnt match the drawing). It was in Manual from the factory! I spent a lot of time trying to get it to work. Once the switch was placed in AUTO it worked a lot better!