I have an ’08 plate 2.0tdci, 140bhp manual. I have no experience of other versions, but this one provides a nice balance of performance vs economy. On economy, I have had 50mpg brim to brim (700miles plus on a tank), though this took a lot of restraint – not dawdling, but not rushing either. Mine has done about 50,000 miles now and economy has steadily improved. 45mpg is readily acheivable – and don’t beleive the trip computer – it exagerates economy by 10%.
I’m sure your sister has extolled the car’s virtues. It does have some downsides to my mind. Enthusiastic driving will eat through front tyres and new tyres are dear, they have a high load rating that bumps up the price. There is no spare wheel, or even anywhere to put one if you were to buy one. The steering lock is poor – a three point turn becomes a 5 point turn etc. If you get one with blacked out windows, visiblity for reversing is awful in the dark – ok if you are used to a van perhaps, but a bugger when you have to wind your window down and poke your head into the rain to back onto your drive.
That said, I’d struggle to think of a car that suits me better right now.