Almost 8500 miles on my 328i 6MT, and I've always logged my fillups on fuelly:
http://www.fuelly.com/car/bmw/328i/2012/shesser/267998
I voted "exceeds expectations" because I've been able to get 34-37 mpg on the highway consistently without much effort while doing the same speed as usual (~10 mph over the limit to avoid trouble with the law). I drove from PA to Montreal in June and was able to plan on going over 500 miles (did 514, mostly with a/c) on a tank to avoid higher fuel cost up in Canada and northern NY. I think 550 miles is doable without breaking too much of a sweat.
I don't do much "city" driving and I'd call my mix 20/80 city/hwy, so the worst I've seen is 25-26 around town. I toggle modes here and there, and leave it in Eco while cruising down the highway.