I tested the protector when I received it. It does hold up water despite the fact that it feels like fabric. I used it on my LUXE mattress, and I still feel the cool gel of the mattress through the protector.
We bought the GhostBed mattress and pillows for our lake house and like it so much better than the much more expensive mattress we have at home. Guests raved about the cool pillows and always want to know where we got them.