Compared to running Windows XP on bootcamp right on the metal no virtualization and then running VM on a Macintosh Pro tower using VT-x how much performance do you lose to VM overhead? Currently I am using a Macintosh Pro 2.66 system and surprisingly the VM running XP is significantly faster than the Dell precision workstation it replaces.
The answer to that question is: It depends on what you are doing. If you are doing simple things like web browsing or some other activity that only needs to run one or two threads and isn't processor intensive, doesn't need advanced graphics, or other fast peripheral access, you shouldn't see much difference between the VM and bare metal. OTOH if you are running several programs that need all four cores and do intensive graphics, you will lose a lot. Nothing like trying your own application both ways.
