[kmike84]

Not sure about the autofocus advice; I'm pretty happy with manual focus. It requires static camera placement, and fixed distance to the person, but isn't this happening anyways? Are people really walking around the room or moving camera between calls?

Manual means there are less failure modes - slow autofocus, autofocus trying to refocus, focusing on a wrong thing, etc.

It also means the hardware can be cheaper - camera doesn't need to have good autofocus (some old DSLR is fine), you can also use manual lenses.