I rarely use the car in full auto mode, in Normal its always in too high a gear around town, and Sport just seems too much the other way. However full-auto + sport is good for some mad straightline acceleration
Typically I use the manual shift, with a combination of the gear stick and paddles depending on where my hands are at the time. E.g. its easier when exiting a roundabout to have one hand on the wheel then change up using the gear stick.
When in manual I use Sport mode as I feel its a little quicker off the line than in Normal, but that could be my imagination
I don't go easy on the car and get 21-22mpg (UK gallons)