Definitely not the type of mask for submerging. Not to say one couldn't but the design doesn't allow for it.

We have two of theses (triboard brand) and love them. It's a completely different type of mask compared to the traditional style - apples and oranges.

There is nothing i don't like about it. My son would say he misses being able to dive down but he has yet to use his former mask since we got this style.

Why I like it:

Far greater field of vision
Zero fogging or leakage. (Not that I ever had big problems with this before, this style just eliminates any issues)
Comfortable fit, contact between mask to skin is spread out over a larger area
No pulling on my hair

A con would be as mentioned above, these are not masked for anyone who like to dive down.

It took me a bit to get used to it after 25+ years of using a traditional mask and snorkel. It was an odd sensation to not have a snorkel mouth piece.

My mom is a very avid snorkeller and my step dad is a diver. They are on Cozumel this week and will be trying out my mask. I'll report their thoughts.