The cruise line's interpretation of an upgrade is different from what you might consider an upgrade. I don't consider a move from an interior room to an interior room on a higher deck a true upgrade. An upgrade, in my opinion, is from an interior to an OV or balcony room or balcony to a suite. Be cautious when they offer you an upgrade, you could be going from the frying pan into the fire. The upgraded stateroom may be on a higher deck but in a terrible location, i.e., near the atrium elevators where there is a lot of foot traffic, near the galley where it is very noisy, above or below an entertainment venue that is open late (think disco or show lounge). Be sure to check the ship's deck plan before you accept an upgrade so you can make an informed decision to accept or not.