Be interesting to see how this recent trend of putting small heavily turbocharged engines in (relatively) big cars progresses longer term. The engine is obviously being worked pretty hard in this configuration - are cars like this likely to last 100k+ miles?
The size of the car is not as relevant as its weight and the current A4 is relatively light compared to previous generations. The A3 / A4 difference may be due to due to longer gearing too. I don't feel the 1 4 is very stressed in the Avant but time will tell. It's on a 24 month lease so not a big issue for me!