Personally, I would never have a pontoon boat if I were going to spend any
time on the ocean. I know people who won't use theirs even on inland lakes
when the water gets rowdy

I am not on the ocean, I'm on the Gulf but I still stay in the back bay most of
the time. Pontoons are different than a regular boat. They get "wet" a long
time before they will pound you. Things get exciting about the time that the
deck starts going under in a swell and you see blue water over the deck. Prior
to that they are pretty smooth but a lot of water is coming over the top as you
clip the tops of the waves. In a small chop it is a lot better ride than you
get out of a monohull, just wet.
One thing about them, a capsized pontoon boat is still a pontoon boat!
With 6 to 10 separate chambers on the logs, they are pretty hard to sink.
All that said they are still an "inshore" boat, in spite of the fact that you
see plenty of them 8-10 miles offshore here in the gulf. YMMV in the "ocean" or
even places like the Chesapeake bay.