Iam glad I caught this thread as I am interested in Sun Princess and did not realize it was going on sale next week for Fla.
Also B2B are becoming popular and the cruise lines have it done pat.
I would suggest if you know your 2nd room and it is close by, I would walk over my stuff and tell the steward to just leave it in the corner as you are getting off the ship. That is better than worrying if they move it which they will but if you do it without a lot of effort, then it is done and you can rest assure the luggage is there for you.