I can only really comment on the TT course...............very very disapointing ride. Went round it twice on Manx GP week a couple of years back and couldn't work out what all the fuss was about. I was expecting miles of twisting tarmac going all over the shop! Certainly ridden many far more interesting biking roads in mid Wales, the peak district and Devon for example.
Incidently I didn't pay for my trip but had an urgent job to deliver to a waste plant over there, it just happened that the Manx GP was on at the time. Picked job up in Dudley, rode to Liverpool, ferry to IOM, delivered job, rode to a pub on some famous corner, got a pint of shandy and some chips with something that was supposed to be a veggie burger, watched two races, rode round track twice, caught ferry back to Liverpool, rode home!