If you have it setup right you can flip to the other desktop quick, see what you want and flip fast. I haven't seen a good virtual desktop implementation since around 1998 though, and have given up.
Easy to switch, easy to know what you have on each one. Easy to move windows to different desktops. I go years between trying them and always get frustrated by how poorly they work, but it has been so long since my last attempt that I don't remember exactly what annoyed me last time I tried.
If I want to have multiple things open and be able to glance at them at once, how would virtual desktops help with that?