You everyday live in a 3D environment which is human beings natural environment. It has thus developped reflexes for this 3D environment, like looking at someone when speaking to him.
In WorkSpace3D and meeting3D, a maximum of signals are transmitted: voice, glance, emotions, focus... You will use same reflexes and behave like in reality.
Moreover, this environment is wider in 3D than in 2D. You can have many opened applications and still use then easily.