Leigh - I was on the Liberty in September of this year in cabin 8461. This cabin is one floor above and is in the middle of the back of the ship instead of one side. We had a great time. There was no problem with too much motion at all (and I am very prone to it). I found the views from the back to be just as good if not better than the side. Sometimes only one side gets the view in port, but at the back, you will usually get a view regardless.
Enjoy - I LOVED the Liberty!
Hope this helps