ok AFAIK
it's been around for a couple years, and it will do a so-so job that won't suffice in applications where soundproofing is important. For the average home remodel, having some sound deadening is better than not having any.
It is also good as a heat break to ensure that most of the heat from electric cables goes into the tiles and not by thermal bridging and conduction into the rest of the house and outdoors.
david