I love my qtronic. A great match for the 2.4jtdm. Pretty much the best auto I have driven, positive and responsive. Like Rosso, I tend to keep mine in Drive, as it works really well. I only ever use it in manual if I want a much quicker lift off when overtaking on a motorway (knock the stick over and drop to 5th, pass and knock the stick back over to Drive - easy peasy
) - I rarely ever feel the need to do this though. Very occasionally I think I'd have down-shifted before the auto does, and thats only on one or two of the very steep hills in parts of the North Yorks moors near here.
The owners manuals give a fuel consumption combined cycle figure of 5.9ltr/100km for the manual and 6.8 for the auto, so there is a difference there. In terms of MPG, I get 42-44 out of mine, and I'm pretty heavy footed (I don't do much town driving or many short journeys though).
According to my manual, the 200bhp 2.4 does 0-100kmh in 8.4 secs for both the manual and auto. Top speed for the auto is given as 224kmh and the manual is given as 228kmh.
The manual is quoted as 179g/km for Co2 emission, the auto is higher at 210g/km and is more expensive to tax.