Well, obviously, it never got that bad on the ship I was on.
It was very calm when I went though. We went to Cozumel, and various other beaches in Mexico and you can never really feel the ship swaying. The only times we felt it was when we started getting close to land, and it's very little. Once you are really in the middle of nowhere, you can't feel a thing. Funny as it may sound, the only time I, and others, noticed it was when we were in the restroom lol.
Like I said, I don't know how often ships get hit with waves like that, but I'd just make it a point not to go during hurricane season for more assurance.