I did the second ever RS4 day at Silverstone last November and I was driving a left hooker on German plates as they hadn't come out over here yet.
I think your take on it will depend on what you are expecting and what type of track days you have done before. I had done little else before and had a fab day, but don't expect to blat around the track in the car as fast as you can on your own all day. But then I wouldn't expect them to let Mr Novice out in a £50k car on his own without some guidance first.
We used the south circuit of Silverstone which includes Hangar Straight (145mph) and Stowe. There were 24 people in 12 cars, so sharing the car all day from 9am to 4.30pm or so. My advice is to target someone who looks like they will have fun too but does't look like their only objective is absolute speed, so you enjoy being a passenger too (the first Audi Experience day I did, i unfortunately had a guy who thought that the principle behind everything was to drive flat out regardless, which, apart from being a tad scary as he careered off the track, meant that I didn't really enjoy being his passenger that much as he never felt in control, especially at over 100mph - the RS4 day I partnered someone who wanted to learn and also have fun, so we probably both got a lot more out of the day).
The instructors are always outside the car watching you and talking to you on radios. 30 mins briefing on the car and then into various exercises on fast lane changing and the effect of abs, the difference of having ESP on and off (the RS4 can have it switched off completely unlike the A3s), how to get some decent oversteer and then how to hold and correct it, guided lapping of the track and how to position the car properly. The day ended with free lapping of the circuit. A few laps then back in, swap with partner, then another go myself after they had had a go.
If you think of it as a day where you get to understand what a decent car can really do (and can't), its limits and also learn a bit about car control under the guidance of some pretty decent Audi instructors and I am sure you will enjoy it. Just make sure you press the S button on the steering wheel!
