One quick follow-up - Mask cushions are specific to the mask, correct? For example, in order to use the memory foam cushion I see for the F20 mask, I need to actually have the F20 mask itself. The foam cushion won't fit into a Quattro mask? Thank you so much for the help! I appreciate your replies.....

I am interested in trying the F20 mask. I would like to see if the memory foam cushion will work better for me than the standard cushions that I use with my Quattro Full Face mask. Would the F20 mask fit with the hose I'm currently using for the Quattro mask? I've been having some problems with leak...