Not sure if runners that train by running in small circles are concerned about evenness and try to run the same amount clockwise and counter clockwise to even things out.
Indoor meets often had 200m tracks with tighter (frequently nonstandard!) radii. The good ones were banked, though it never seemed to be at the right angle, always too steep or too shallow.
Every race still goes counterclockwise, though.
Maybe it's my XC side talking, but I'd love to see a track in a figure 8 with an underpass. Left turn, over the bridge, right turn , under the bridge, and repeat! It would break up those monotonous 8 and 12 lap races nicely, and you could fit a longer track in a shorter rectangular building by using the hypotenuse. I'm sure people would hate the hilly incline, though...
But I would love to see it for medium distances, just to see what crazy stuff would happen!
The curves felt great for me though, I really liked the 200m better than the 100m. Can't imagine how shitty it'd have been for a left handed fencer to run track, because the big muscles would be on the inside leg.