there are flaws in that article.
but it's a nice read anyway...
it does say hardly noticeable... ;-) which means it is noticeable.
frankly, i'd rather have mpeg2, since mpeg4 is so cpu demanding.
since the cable industry chose mpeg4, i don't doubt mpeg4 specific hardware acceleration is far behind =)
i will say mpeg4 is a nice alternative to mpeg2.