[timje1]

Uncanny valley, here we come. Studies have shown that people are more at ease around a robot that tries to look like a cute humanoid robot, rather than a near-human but not quite construct.

Replacing the video feed of a person's face with a computer generated, almost-their-face-but-not-quite simulacrum sounds like it'd heavily increase user nightmare rates.

[Crito]

Maybe it is just me, but with a disembodied head rolling around on a segway, we are already rather deep down in the uncanny valley. Removing a bit of humanity might just pull it up the left bank of it.

[Houshalter]

It doesn't have to be realistic looking. Just use any game avatar system that seems to work okish today.