My dad was in retrospect a Piech guy.
He lived on a steep hill with Iowa winters. So he bought a 1990 Audi 100 5 Cyl but FWD. Then he bought a 1988 Audi 80 AWD for my mom. Then my dad bought a 2002 A6 AWD V6 to replace his his Audi 100. He also had/has a Mercedes 300 turbo diesel.
All of those cars were owned without major issues. But I am no fan of Piech. I think Piech demanded the impossible and would accept designs that worked well for a while but rarely for 100,000+ miles.
Now Piech would blame the customer for this and their not maintaining the cars as prescribed. I suppose he thought the cars were too good for them that complained. But my favorite shop has a never ending parade of less than 10 year old VAG group products undergoing engine and drivetrain transplants that might suggest that their cars are less than brilliant for the average owner.