I'm on 10.8 - I just tried it and can't get past the spinning beachball. The earlier one I have still opens (build 270198) but unfortunately I can't seem to get all three texture fields on my avatar (head, upper, lower) to completely render at the same time, so I end up having to resort to Firestorm:(
ETA: Well, turning HTTP Textures off then back on seemed to fix that rebaking issue, so back to using the earlier build.