I have a very well cared for and healthy B5 S4, stg2, stock turbos. And I'd choose the S4 over the RS any day for canyon craving. The S4 is smaller, lighter, and much more nimble in every way. The RS6 will hand my S4 its ass in a straight line, after all it has about 150 more hp, but I still choose to drive my S4 for fun drives. And it doesn't help the RS6s case that it is a crappy auto, and my S4 is a 6spd. I love my RS6 for highway cruising and hauling my family around, but in my opinion, I enjoy my S4 more.