This is my fifth Insinkerator Hot Water Dispenser in 22 years and three houses. They are very easy to install. I'm not a plumber, just a guy who is not afraid to try to do something around the house. 
Having hot water immediately available is VERY convenient. I install one each time I move to a new home.
The only down side is that they last about five years then have to be replaced. After about five years, something causes them to sputter which spits out hot water and burns my hands. But, replacing them is easy.