If you have at least a 720p monitor, Anti-aliasing is pretty much useless. There is a difference, but not enough to make up for the way it can tax a system.
If you don't already know, Anti-aliasing basically removes the 'jaggies' on screen rendering everything smoother. However, on an HD screen, there isn't much of a difference. It also puts a huge tax on your hardware, especially when rendering 200 units. This is because it is applying anti-aliasing to everything, not just to individual pixels. (I think
)
Either way, though, I think M&B uses processing power and graphics power poorly, leading to low performance even on high end systems.