well at racing school my instructor was talking about awd, and audi and subaru came up, he said the main difference is that audi awd is more mechanical, while subaru awd is more electronic and high tech, so subarus is kinda like a traction control system and audi's is just pure plain old awd. and in performance neither really are "better" it depends on the driver, subaru's are much easier to drive and control, but it is limiting in what the driver can do, while audi's are harder to control because it depends alot more on the driver to control it where with subaru the car itself does more, but for that reason a good driver can do more with an audi than a subaru because they have more total control over the car.