Well I have 475bhp from my B8 and I am still seeking its limits - I am convinced that they are higher than my own driving skills, I have never ever felt that the handling of my car has been less than I need. So if the B9 is better then it is way better than it needs to be for the performance of the engine (in the S5 - not sure about the RS5).
Gary, I'm not sure what your previous car experience is, so sorry if this insults your intelligence: Are you fully away of the difference in characteristics between the B8 supercharged and B9 turbocharged engines? My own experience has been many years driving turbo cars and when I came to the B8 I fell in love with the characteristic of the supercharged engine. So much that I am unlikely to buy a B9 RS5 despite Audi's chassis improvements and the very tempting tech. But this is a very personal thing - there are plenty of people who love the higher peaky torque that only turbocharging brings. If you are not familiar with the difference based on test drives then I urge you to do so before making a decision on buying a B8 or a B9.
