wouldn't a seat tube with a steep angle w/ a layback post make for a body position that would be farther over the rear wheel for theoritcal gain in climbing ability? It seems like a good idea for a race frame.
BTW, I've got a lemond with a 72.5 degree seat tube, and I've got a layback post and my seat is 2/3 of the way back on the rails. I love the feeling of a slack seat tube.