Update another thousand miles on:
(2018 3.0 TDi Quattro Sport Avant , so 218ps not the 272 engine, but auto)
There is a noticeable lag when pulling away from a standstill. With engine running and park brake off, in Drive - but any mode - foot off brake, gently on to throttle, revs rise but nothing happens for just long enough to think "more revs" and press harder - at which point it pulls away and all the power comes in suddenly. Appears to be gearbox management, not engine.
The rest of the time it's fine: overtaking, kickdown, whenever. Smooth, quiet, feels well-planted and the quattro system feels as if it could defy all the laws of physics in a wet corner.
Shame about the take-off....