I have been in a unique situation to drive the 05 B6 for 6 months/ 35000 km and have just taken possesion of my post accident B7.

The differences between the two vehicles is mind numbing. Stock to Stock is 10x better... and it seems faster than my modded B6. The handling is better overall, the lighter steering makes parking garages etc a dream..and it stiffens up nicely under loads. The 2.0 pulls very strong and is soooo smooth. (ulra smooth). It doesn't complain about being revved up (seems silky at all revs). Even without the power passenger seat and the tilting mirrors etc etc etc the car is much better.

If the choice is B7 vs B6 I would go B7.