That is interesting - so there was a Celebrity which was more basic than the Constellation and a Celebrity which was more advanced. The Constellation was a half way house so to speak.
I personally don't see a real need for it either, there after all was nothing wrong with wheels, or even the sliders to a certain extent, but the floating idea did take off (as a gimmick or not that is debatable) but hey ho, it makes it what it is today - a desirable classic.
It is a bit like the Dyson "ball" I suppose, something which some say makes things easier and some see right through, but they all consider buying... Well, except for me, I hate Dysons...