I had a semi-crash. I thought I was headed for the desktop, but then the game stabilized and continued on for another hour or so until I quit for the night. Remarkably stable after those last two.

The initial game settings were Medium on my system, which is a quad core with a GForce 275 card. It was pretty good a couple years ago, though it is out of date by now. However, last night I boosted the sliders way up, and it is still running fine. Just what would I get out of High or Ultra settings?