Gsheen...
The early Vorwerks did not have hoses, but were light enough to swing around for above the floor cleaning. Our metal casting, molding, and stamping technologies are so much more advanced now. How light could we get a full-size upright to be? The back end of the wheel carriage would have to have enough weight to counter the pull of the nozzle on the rug so it would not pull the rear wheels up at all. The motor-fan unit could be very, very light. With the advances in motor technology, how small, powerful, and quiet could it be?
I suppose a full length hose could be included, or available for use as a tank-type unit, but with properly designed wand and tools, I see the almost complete elimination of the hose. A telescopic straight wand, a curved wand, a dusting brush, and a flex crevice tool, a floor/rug tool with a clip-on felt pad. The main tool would be an upholstery nozzle with a swivel neck with three slide on shoes, standard crevice tool, wide dusting tool, upholstery with stiff brush at the back, with red lint pickers behind the brush and in front of the opening.
With a super powerful, super quiet, super light unit, giving the belt lifter more leverage, and making the conversions from one unit to another easier, including the second motor unit to keep set up as a hand unit, I think Kirby could take the market by storm once again.