Andrew,
Your first question is a bit like, 'How long is a piece of string' as it depends on what you are comparing it with. Also, I'm no track-fiend so I'm not sure I'm qualified to comment anyway!
That said, the acceleration is mind-blowing and the steering very direct. Turn-in is very rapid and there's loads of grip. At Goodwood last year I was intrigued to discover that you could hear the amount of slip on the wheels and that breakaway was very progressive and quickly corrected. My only concern might be with being able to get large amounts of opposite lock on quickly, say in the wet.
I am 6' 2" and when I bought my car, I couldn't drive it. The GTD pedals were too close together for my size 11 hooves and I can't think of any time when I would ever need to press all 3 pedals simultaneously. However, a number of options were open to make more space:
1. Remove the seat from its runners and bolt it direct to the floor. This produced 7/8" of vital headroom and at least meant I could shut the door.
2. Install a Gurney Bubble. This was probably the most significant factor in allowing a reasonable driving position, which because it's almost completely reclining, is very comfortable. I have worn a helmet which, as long as you engage your head in the bubble while closing the door, works very well.
3. Remove the old pedals and install Tiltons with separate master cylinders and a brake-balance bar. Custom-built pedals, to optimise the throw available were necessary, but they also allowed almost infinite adjustment to ensure everything was spot on. I have also invested in a pair of casual trainer-type shoes which have no welts, so my footprint is of minimal size.
I have since driven the car to Le Mans and back, did 3000 miles last summer and am well on the way to another 3000 this year. The only thing I notice (for about 5 minutes) is the offset seating position, with my clutch foot on the centreline of the car and the throttle pedal heavily displaced towards the centre by the wheel arch. You have to be absolutely sure you have the clutch pedal when doing a racing change into a roundabout, as getting the brake pedal with your left foot causes clouds of smoke and very frightened following drivers!