If they both use patterned light I would assume they both have this problem. The patterns need to be big enough to resolve, so that limits the resolution near edges.The second YouTube one shows lag similar to Natal. You can also see on the silhouette errors in the camera's depth perception. I wonder if Natal has this too?
I really wonder why time of flight has to be so expensive, it seems to me to be a rather trivial variation of CMOS image sensor (you "just" need nanosecond precise timing for the reset and the transfer gate across the entire chip). Shrug, probably a patent issue.