I would tend to disagree (RESPECTFULLY) to a point. I would agree that smiling, wrinkles, and the vast majority of leaks are at the top. But I have had leaking problems at the 'stash. It tickles a little. The water pressure overcomes the internal pressure in the mask and you have a leak that can come from anywhere, that is why when you have a good seal you will experiance a mask squeeze and need to breath out the nose a little to equalize the internal pressure with the ambiant pressure.

I have posted before that on some occasion I only have to remove my reg, and swipe my hand downwards from the nose pocket to remove any stray long hairs.

I think you make a valid point, I also think that the mask itself maybe part of the problem. The fit in the shop may not be the same once you hit the water. (just a thought)