to Brian, GG question

[Ido]

Brian, dunno if relevant to ask, but in case it is,
there are relatively new drywall boards made of fiber-cement
(such as http://www.sheraeu.com/Boards.html),
don't know enough about them, but the specs and sample I've seen look very promising.
do you have any input to share regarding GG with fiber-cement or with fiber-c combined with standard gypsum drywall?
take care,
Ido