martine-
i'm hoping i never encounter anything as bad asa flood in my kitchen with or without greenboard

.i've certainly considered your point, though. if we were to be flooded no material would make any amount of difference...it would need replaced. as said before, this issue probably makes more sense to bathroom remodelings. my brother-in-law used it in his laundry room where the drywall would come in contact with splishes and splashes of water and he seems to be really happy with the material.
we're calling drywallers today for estimates and we'll see what they have to offer.
thanks,
jackie