It is not a "queezy tummy" that would put me off, but a tired, old 1970's C152 which has been abused as a training aeroplane all of it's life.
Funnily enough in 9 years of flying I have yet to put myself into an unintentional spin. I did end up upside down once, falling with style...........with the aero's instructor sat next to me laughing at my poor attempts to recover from the upside down stall at the top of the loop. I had left full throttle on so we were hurtling earthwards rather fast so I guess he though he better help me out
I agree with sentiments that "advanced flying" should be taught but I think it is something that people should do post PPL when that have built enough confidence in day to day flying that they might actually start becoming lax. I never did complete my aero's, maybe something I should continue this summer.....