It's a microscopic sample size, but with the OR developer kit I got to play with, probably half women I know who tried it felt motion sick; the proportion was much much lower for men (maybe 1/10).

At the time I simply put it down to the guys having played more FPS games and being more accustomed to it, but its interesting to read this.

On the other hand, with the precise head tracking in OR, I wonder if a higher-resolution with a better lighting model would make this issue go away?

It's basically just tiny head movements, right? As you move you see minor shading differences in the scene, and use that to mentally reconstruct the 3D geometry (as I understand it from the article).

You'd think high precision head tracking with a sufficiently high frame rate would be able to catch that.

(however, the low res / poorly lit OR demos probably don't)