In a test drive at highway speeds I was able to get 44mpg. I would compare it most generously to my first drive in a Prius.
The one thing I didn't like about the C-max was the turning radius. It was like navigating an aircraft carrier.
My wife test drove the C-Max while I rode in it. One shorter drive, one longer (45-60 min) drive. - Only got a bit under 40mpg. - Found the gas pedal over-responsive, at least at lower speeds. (But she wasn't unhappy and figured she'd get used to it). - Liked the ride. - Not sure on comfort since it was a day with a lot of driving. She liked the car. If she/we tested it again I'd want to try an Energi since it could cover her commute. I didn't like the car, because I judge cars by fuel economy and all-electric range.
I drove both the Hybrid and Energi C-Max models. The hybrid only returned 38 mpg. The Energi returned 54 mpg on a 4 hour round trip to lunch in Carmel by the Sea. Needless to say, I purchased the Energi and love it. I have no problem beating my Prius C mpg numbers in hybrid mode, not using the EV range. Using the EV range, I get about 28 miles per charge. My MPGe mileage is currently at 69 mpge and rising