Hi Horti,
Castle Combe is a small track with only 1 big straight that has a bend in the middle of it but you can still see 130mph at the end. The biggest concern is there is very little run off before you hit something solid but having said that, i like the circuit.
The JEC event there is really well organised and very friendly, informal (other than safety breifings) and has excellent track manners, you have to wait until the person in front signals you past before overtaking unless it's a straight, this stops all last minute braking, crazy dives up the inside into the corner type idiots.
Once on track you forget the F's weight although hard braking is required and the change of direction feels great to me. Certainly there are much more nimble cars but not many apex focussed machines have 12 way adjustable seats. I run Michelin PS4's and they gripped in the morings wet track with no front wheel loss of traction and the back could be spun out under control with no sudden loss of traction, very progressive.
In the dry they gripped far beyond my bravery and with really enthuastic driving the rears rarely let go on the exits and the fronts never lost traction into the corners. DSC was in track rather than off and I used the paddles as I prefer gear shifts either before or after a corner, not mid way through. Used dynamic all day, no sound issues, think I was 96 or 98 Db and a noisy car is always faster.
Overall, really happy, only issue was I could only do 5 lap stints as the brakes got very hot. Even after 45 minute rests you couldn't touch the calipers. I think I did 5 sessions of 5 or 6 laps during the whole day and that was enough for me (knackered) and the car (hot brakes).
Very impressed with the R on track and would be interested to do more, let me know if you have any plans. Which model do you have?