The Qtronic is the best auto I have ever driven. You can hardly feel it shift and in sport mode it is very snappy. I haven't used manual mode much yet but when I did it was very responsive. Personally, I can't see the point in the fancy twin clutch Selespeed sort of boxes because they add complexity and unreliability from what I have seen. With the Qtronic you get paddle shifts with tried and proven reliability. I think you should have either a straight manual or a torque converter auto like the Qtronic. The auto is perfect for the 2.4 JTDM because it seamlessly keeps the engine in its power band all the time. With a manual you would be rowing the gearstick a lot. I think performance is probably better than a manual unless the driver is able to shift at the perfect time in every gear.
Just one question to other Qtronic owners: Am I right in assuming that you can shift into manual mode whilst you are driving? The handbook doesn't actually spell that out.
2004 GT 3.2 V6, Grigio Stromboli
2008 159 ti 2.4 JTDM Sportwagon, Grigio Stromboli
1989 75 3 litre V6, black
1988 75 3 litre, red, (son's car now)
2000 156 TS 2 litre, Cosmos Blue, (daughter's car)