Let's keep customer service seperately.
The RS4 is sure a great all-round car. I would see it as luxury car for general use... that also happens to be (very) fast.
As opposed to a fast brute that also happens to have 4 doors (e.g. Scoob or Evo).
I had chosen it as it was probably the easiest fast car I could 'sell' to the wife.
Its main quality is the fact that you can use it to munch thousands of miles while still being able to give a 911 a run for its money.
It is also very easy to drive fast. Accelerate, brake, steer. No need to be worried it will bite back at you.
But as such, it has plenty of competition, especially in countries where 4WD is not a bonus: M3, 997 and 997 S, C55 AMG, etc.
And in that group, my choice would definitely be a 997 C2 with PASM in the UK. Similar cost in HP or Contract Hire but more character, great sound and safer investment.
For weekend use, I prefer an Evo or fast Scoob, no contest. Much more brutal and more entertaining to drive (if you enjoy fighting with the car at least).
If I could only have one car that had to be fast and transport for family holidays, an RS4 Avant would sure be in my top 3 (together with the S6 and probably the E63 AMG). I don't think it should be compared to Evo or Scoob though.
Thank you to Audi by the way, for giving me a brilliant excuse to revert to the Jap rally machinery.
"Sorry honey, but Audi just moved the delivery 6 months out and say they can't do the quote lease price but want 30% more... Let's get another 4WD saloon"