The Ultralux is the newest of your list. The Olympia has the old type powernozzel that is rectangular. The rest have the new L shaped powernozzel and the brush is longer. As to the performance, the three newer vacuums should be the same. If the vacuums are used and not rebuilt, I would select the Ultralux. The Marquise had a motor issue when they came out and if the motor has not been changed I would stear clear of it. I changed 37 motors in one month under warranty. They did rectify the problem with the later models of the Ultralux.
Joe