Interesting but rather sad thread. I drive a 1.6 4/4 Sport with a third of the power of a Plus 6. The 4/4 is fun to drive with plenty of driver involvement. Its not perfect and I can upgrade the cars handling and performance if I wish but I would also be happy with the car as it is.
I haven't driven a Plus 6, I don't aspire to own one, and if I did I would probably use a fraction of the cars performance.
So for me there would no point owning one, and it wouldn't be fun to drive one either. Especially as the Plus 6 is 13" wider than a 4/4 and I like to drive on rural roads.
I agree that some driver training should be part of new owner package. I suppose I would say that as I work in driver training. I am not easily scared though and would hate to be a salesman sitting in with customers on test drives in the Plus 6!