Audioholics has a great list of their experiences with less then stellar demos. Of course Monster Cable is on the list with their "Our cable vs their cable routine." Even big name players like Toshiba's demo of HD DVD did not work. A Microsoft boy put in a HD DVD disk and nothing happened! (Once again, think of Bill Gates plugging in that scanner to demo Windows 98).
Some things on the list will just make you smile and shake your head.
[Thanks for the tip Akia!]