bootcamp over parallels
i found that autocad on parallels hangs a bit, especially when working with large files or with x-refs and hatches. im not entirely sure i am explaining this right, but with bootcamp you get full use of the processor & ram, where as with parallels, part of your processing power goes to holding onto mac apps, which allows you to switch back and forth. i was advised by other mac users that bootcamp was the way to go. autocad, rhino, revit, maya, cs2, no problems at all with bootcamp.
i just switched, and it works ok for me. hope this helps.