Bid.., you will have already equalized your pressure, only it's with air not water. If the mask floods, or an ear cup floods you will only have wet ear(s), no pressure differential.
Chip, your comments are true, but as you admitted you only used the mask once. I don't have an over pressure issue from beathing into the earcups constantly. I found if I over breathed through my nose the excess air would simply bubble out of the ear cups. It just creates a new underwater equipment sound to ignore, that's all.
I find the sounds of the bubbles from my reg, passing by the sides of my head, to be muffled and less intrusive.
Spratman, who cares how you look diving? We all surface with mask rings on our faces and buggers hanging out of our noses.
One last advantage with the Pro-Ear mask, fish can't nip at your ears. Freshwater sunfish can be really pesky in this regard. You'll be sea-lice and jellie proof too.