I did an event at silverstone, it was in a supercharged exige (i owned a n/a and was trying to figure out if it was worth the extra four grand) the drivers/instructors are all properly qualified and ex- racers or in race series themselves.
On other tracks that isn't the case. They highlight that quite a lot for a safety point of view.
Was a bit disappointed it was the small circuit inside the silverstone track, and not on the track itself.(possibly stowe, can't quite remember the name)
However due to not riiding a bike anymore I found that my concentration wasn't quite what it used to be and by the 4&5 lap I was making small mistakes I hadn't done in the first 3 laps. (wide on a on an apex, and not quite in right position for sequence of bends)
I had outlap followed by 5, then lunch, and another 5. I think that was the most I could have done, as after 5 laps I would have started getting sloppy.
After the initial disappointment of not getting out on main track, it was a very very good day.
Passed ferraris, aston martin, and lambos.

And the tutoring was spot on, was encouraged to push harder on every lap.