Bought my 159 in March. I went down the 2.4 (200bhp) automatic route ('08 plate). Got the lusso spec, on 17" wheels. Cost less £7k (44k miles), but to be honest I've spent nearly half that again to get the car to a decent state (probably should have read some of the posts on this forum before I bought it - lol).
I've had DPF removal/EGR blank (sorted out the lumpy regens I was having), remap, cam belt/water pump (really make sure this is done!), MAF/MAP and other sensors replaced, front suspension (both sides) upper and lower arms, full set of halfway decent new tyres, tracking/wheel set-up, proper servicing etc,.
The car is beautiful, and now runs like a dream - lots of smooth power, great grip, sounds gorgeous (for a diesel) and is not too bad on economy so combined is now over 40mpg (was around 35-38 before map), and I'm not exactly light footed - lol). The qtronic is amongst the best autoboxes I've driven. The Lusso spec is really nice and comfortable (although mine has no satnav - but then I'm old school and like maps!). It is a really nice place to be as a driver, and it has lots of presence on the road. I love driving this car - I find excuses to go out in it :-). So glad I didn't go down the VAG/BMW route (which was my original plan when I was looking for a new car).