You can't do worse than you are guaranteed is the basic premise here. I was lucky and was upgraded, but don't book lower that you will be happy with expecting an upgrade. My group all booked GTY. 2-booked gty 4a, and 6 booked gty-6a. The 4a got 6a rooms, and the 6a got 8b rooms. This paid off for the cruise line in the end, as 4 of us have decided we can never have less than a balcony again!! We booked our next cruise GTY 8a.