Some of the people who were with us said hey felt nothing except the night we left Cozumel. I think we were in some of Bill then. However on the 7th deck at night my fed "rocked us to sleep." The first night I thought (first cruise) oh I am never going to get any sleep unless I can sleep with my eyes open, but by the third night I was use to it.
I went to my daughter's room on he first deck and I have heard you are not suppose to feel anything on the lowe decks but her whole room moved to me. I think it is your state of mind, you know mind over matter. After all it is a ship and it is going to rock some.
I would say 95% of the time I felt nothing after I got used to it.