I use a Mac running on Intel Core 2 Duo and it is bloody fast even with the acceleration flag set to disabled. When I use this set up I am not able to simulate the experience of the average user's computer (800Mhz - 2GHz) because all my scripts run so bloody fast. But if I switch off Intel's VT-x support, the virtualization is bloody slow, like a 133 Mhz computer. I would like to suggest some sort of speed control for me to simulate different speeds of the computer.