'Rube Goldberg' machines and the like would appear extremely similarly if not identical to all clients, assuming there is no lag.
Exactly, I think kompressor just didn't want to give everyone false hope, opening the way for people to complain about it being out of sync. I think with good latency, physics would be in sync enough for people to see some cool things together.
By the way, for those of you wanting avatars to fall apart, why isn't it possible now? You could hide the avatar on death and spawn body parts that bounce can't you? They did it in TBM I believe, but maybe the way the avatar's pieces are animations would make it impossible.