It seems there isn't a verdict out on this yet. I actually have 2 setups-- for my shamans it's slaves using one folder, main using another folder, both on the same HD. For my new group I'm running them all on the same folder. I haven't noticed much difference, other than they want to use the same video settings. I don't have any crashes on either setup.

Has anyone done any actual tests or have any figures to show one is better than the other?