I have used an evapotranspiration (ET) control system for years using home automation equipment. Just because of the type of person I am I have a hard time leaving the system alone to do it's job - basically I like to mess with things and I am always making changes and adjustments to things. In past years I was never very happy with my lawn and I always thought that it could be better, but this year I swore that I would take the hands off approach and that I would let the computer do it's job without hindrance from me and honestly my lawn has never looked better.
I will say that I think that the system waters a lot, but I can't argue with the results. The next picture is the school across the street from me, they don't water but you can see that it has been a tough year for lawns here in Illinois.
So after this year I am a huge fan of ET, I don't pay for my water so I can't speak to the potential water savings, but for a high quality lawn it is the way to go in my mind.