Wow. Thanks for a very informative reply. I've run the square Nitto setup all season and have been happy with it. I ran my daily driver 255/275 Michelin Super Sport setup at Watkins Glen a couple of months ago when it was cool and foggy and it showed me just how much better the car handles on the track with the 275/35-18 NT01s. I had naturally assumed that the better feel of braking and turn-in with my track tires was due in large part to the wider front section width, but based on what you're saying regarding contact patch shape, the track tires are probably better mostly because of stickier compound/tread design.
The 285/30-18 BFG R1 square setup is an interesting thought--has anyone run that tire in that size on the front without rubbing issues?