I'm a huge fan of the Royal Prince 501. I own three of them. I've had opportunities to get plastic Dirt Devils that replaced the 501 but they've never interested me except possibly as a brush roll donor.
That said, I recently acquired something entirely different in the form of an Oreck XL mini vac that's more like a scaled down canister. There's no provision for any sort of power nozzle but it does have enough suction to spin a turbo brush.