When we book a cruise we generally don't pick a particular cabin but rather we pick a cabin category. That way we are guaranteed a cabin in that category but may get one in a higher category. A higher category may not necessarily mean a larger cabin but may just mean one toward the middle of the ship. (There is less "rock and roll" in the middle of the ship which is why they are more expensive.) We have generally been pleased with what we have got.
When we booked the cruise that starts tomorrow we asked for an AB category cabin - outside with a balcony toward either bow or stern of the ship. A week or so ago we were assigned an A category cabin - toward the center of the ship with about 230 square feet. Not a bad cabin and an upgrade from an AB.
This morning I checked our reservations on-line and noticed that our cabin assignment has changed again. We have been assigned a SY cabin - a suite on one of the upper decks with about 360 square feet. The cruise line must like us!