When I first got my C-Max I used Eco Mode but I don't anymore because I can't stand the throttle lag and inconsistent throttle response! Often I need to pull out into a main road, but in Eco Mode I mash the gas and the car sluggishly starts to move. In normal mode, the response is immediate and you get a really nice push of torque from the electric motor. And it doesn't mean you can't drive efficiently. You just have to control the throttle yourself instead of relying on the car to slow you down. I guess in a way it trains you to feather the throttle rather than just mashing the pedal all the time.
If you're driving in Eco Mode I recommend trying standard mode!