Just to share my experience on this. I collected my car 19th December and how have about 1,300 miles on it.
Initially I made no effort to get good MPG and have been enjoying the grunt a bit too much to focus on MPG. In the last few days, I thought I'd be a bit more sensible. Without much effort at all, I get around 35-36mpg (indicated) in town driving, with a mix of stop-start and 30-50mph stretches. On the motorway, I get 60mpg easily at 75mph, but this seems to drop a bit to mid-50s if I let the speed creep unto 80.
I initially thought Eco Pro was a waste of time, being so unresponsive, but it helps create a really relaxed driving style in city and suburban driving and I have to confess to liking it.
I'm very happy to see these kinds of figures, even if the on-board computer might be being a bit optimistic. The motorway MPG is impressive, but I'm startled by how good the car is in city and suburban driving. Impressive, given the grunt you have to play with.