One each for sections and tracks, graphic editor, mixer and lastly plug-ins and effects.
Each desktop can be named so you know where you are even if its not obvious by the windows onscreen.
It's a weird thing to use metro with SPACE to spare!
You can setup the function keys to switch between any of the desktops....all the while anything actually on your desktop (like folders) appear in all desktops.
The cool thing is if you have the transport window of metro in float mode it also appears in every desktop.
Start virtual desktop before metro and it remembers all the window positions after you save your preferences.
I don't know if I'd go beyond the demo though as I'm so used to having everything on top of everything else and accessed all at once.
It would be a different story with a quicker CPU (or at least one with quartz extreme and a better video card).
Below: the 4 desktops how they display in virtualdesktop's page layout which helps you move windows about. Safari window writing this message is sitting over the sections and tracks desktop. OSX dock below it.
scoot.