Just different beasts of course.
I must say however, the RNS-E in the allroad is kickin'. If you have the means, I highly recommend getting one.

Oh, and what wheels were those on the S4?

I'll probably put on the 18" RS4 replicas at some point, but I don't plan to chip the allroad.

The S4 wheels are Flik Justice 18x8 with 225/40R18 Kumho ASX tires. The only place I've seen them sold is Edgeracing.com. They've run some killer sales over the years. The wheels look great new, but don't wear well in my opinion as the finish flaked in a couple of places. Most would never notice it though.