I agree with what everyone has said, they are some cool uprights, and those are good recommendations. I've also been looking at some of Dirt Devils central vacuums, they have a whole lineup and a nice assortment for generally different houses and situations. The Power Pak and can vac canisters are very nice, I have not found one for a good price with its powerhead yet though. I just gotta keep waiting and something will come along. They made a lot of different variations of the Power Pak. They even used to sell Can Vacs with the power nozzle port in the handle section, and sold power nozzle kits at Walmart and such so you could convert to a Power Pak.
I think if you can find an Ultra MVP for a good price, especially a Magnum MVP by Dirt Devil, get it, they are what I've heard to be the best Dirt Devils that Royal made.
My advice is to not pay over $75 for any non-TOL used Dirt Devil. That'll save some money.
Regards, Garrett