I have found with my 2012 F150 EcoBoost I have my choice between Eco or Boost but not both. Same on my wife's 4 banger EcoBoost Lincoln.
Another thing I have learned about cruise control: if you have a heavy foot and a touch of aggression (Who? ME?), using cruise control to stay at an economical pace can save gas. Keeps me from trying to keep up with faster traffic and dodging for those openings in traffic.
HOWEVER, if you use self control and maintain an economical pace, you will get better mileage by regulating the speed yourself. Going down hill? Allow it to pick up a little speed and use that excess getting up the next hill. Instead of giving it the gas going up the hill, try and maintain even gas peddle pressure, keep that turbo from spinning up. Cruise Control is constantly giving it gas and letting off to maintain steady pace, working against gravity and momentum instead of utilizing it.
I rarely get the mileage figures claimed for my EcoBoost but I have taken a few occasions to really try and have gotten some pretty good numbers. My wife drives me crazy, on the gas, off the gas, on the gas, off the gas. I can get a couple more MPG on her car than she does.