As jhp has mentioned, upgrades can be a mixed bag. Often times, it can mean a suite on a higher deck but with no other amenities ... and higher means farther away from the dining rooms, shops, theater, casino which may mean a longer trek for you. It may also mean a move more fore or aft than you were originally which may mean more motion in your room.

We've booked a guarantee before on RSSC and got upgraded and was lucky enough that it was still a relatively central location. It was kind of a pain though going up and down all those stairs though ... :)

Masaki