Weird that your experience should be so different to mine. Mines a 2009 but has the same engine as yours. You're not 28 stone, I take it?!!
I wouldn't have hesitated to recommend the i10 for what the OP wants.
Which model have you got? I get 45 out of my 1.2 Comfort, and that's just doing a daily 10 mile round trip to work.
Never done any prolonged long runs, so don't know how that affects things.