I have the '61 plate Mk 3 Focus 1.6 Ecoboost 150PS (petrol) and I love it, but of course the mpg isn't exactly impressive as has been well documented.
It's only got about 17K on it so hopefully it will improve, but I just wanted to let people know that it's just gained a couple of mpg apparently by updating the engine software.
The Ford garage where I bought it recently offered me a free software upgrade (because they changed their name to Trust Ford), so I had it done with the result that my average mpg has risen from 34 to 36 (or from 36 to 38 if you believe the trip computer over maths). Not headline news but better than nothing! No idea what the update did, the bloke I dealt with didn't have a clue.
That mpg is with mixed driving by the way, town & motorway, heavy & light-footed.
Anyway just thought that might help some people.