I move cabinets up and down steps pretty regularly. So far the only thing I ever had to take a monitor out of was a Super Strike. It was just too big and heavy for two guys to handle on a set of steps that had 2 90 degree turns. On that one I pulled the monitor, the playfield, the coin doors, and a few other odds and ends, and then it was EASY.
Of course, a lot of you guys built your own cabinet out of MDF and used a 27" monitor. So that is a whole different kind of creature. Probably more than twice the weight of a real arcade game.