Mine: BMW X4 2.0d M-Sport (Red) Hers: BMW X1 2.0d M-Sport (Black) Sorry about that...
While the IAM course taught me a lot about reading the road, a day at Oulton Park taught me a lot about positioning and braking.
Caveat- the positioning and line through bends on a circuit differs from that required on a public road, because of the possibility of obstructions and oncoming traffic, plus a complete lack of marshals acting as your eyes at blind crests or bends.
I'll give you my take on it as an ex advanced driving instructor.
IAM = Fairly useless unless you are very new to performance cars. Will reach you the basics and good road craft but will teach you nothing about the car.
RoSPA = Better than IAM by a mile instructors are miles better and will try and teach you how to get the best out of your car.
Track day = Good way of trashing your car if you are unfamiliar with exit and entry points and when, where and how hard to brake also full of d*ckheads who think they are Lewis Hamilton.
Driver development day = Best of both worlds half day on track half day on road by two different instructors gives all the basics of exploiting your car on road and track. Best one by a mile is the one at Knockhill which involves a visit to the local police driver training school for use of their facilities.
Not really it was a Mercedes F1 team day we are sponsors and MB' s largest supplier, Lewis was a no show but we were given the museum tour by Peter Bonnington MB's race engineer. Nico took me and 2 of my colleagues out in a CLS 63 one of the runs I was in the back never felt as ill in my life.