I realise it does not run as well in VMWare or Parallels, but for the 2d drawings I am working with, I come across no problems.
If things were to get much heavier, I would have to use Bootcamp, but the ease of use of being able to instantly switch between operating systems far out weighs any performance hit for the ACAD drawings I'm currently working with.
As honolulu says, try it both ways, although vmware does cost money!