Our powershift is very impressive. While the C-max is the wifes / family car I have Crossfire Auto (which is Merc 320 SLK in reality) which I rate as a very smooth box but the Powershift is another stage on. Once moving you only notice the changes from the rev counter drop.
MPG so far from new is around 39.5 overall (2 litre TDCI 136 bhp) which I think is Ok as it includes quite a bit of urban work