Yes, I did say Fantom Thunder!
It's funny, everyone keeps talking about these "infomercials" for them -- I never saw a single one. In 1996 I was walking through the Bed, Bath, and Beyond in Chelsea and a guy was giving them a demo. The cyclonic bagless was still a brand-new concept that I'd never seen before. At the time I had a 1970-something Eureka upright that I'd inherited from an old roommate in Pittsburgh, and it came to NYC with me. It was nothing to write home about (I can barely even remember what it looked like, but I remember the hood being greenish, the bag and handle being beige, and no headlight), but it seemed functional enough, and at the time I wasn't in the market for a new sweeper.
Needless to say, the Fantom blew me away. As we all know, those 1970s-era uprights had pathetic suction in their attachments (and I didn't even have attachments for mine -- it was something I just never got around to buying), and when I saw an upright (bagless!) vacuum that instantly converted to a canister with suction as powerful as a shop vac, I was sold on the spot.
I was actually drawn more to the smaller upright -- it was a dark green (my favorite color) and looked a little sleeker, but the beefier Thunder seemed more powerful, so I figured if I'm buying an expensive vac, it might as well be the top of the line.
That day I put my Eureka out on the curb with a sign that read "still works". It was gone within an hour.