Oreck UK2200 XL Classic are what he sees the office cleaning crews use most often. The other thing that gives this design a foot up on the competition is the thin wire wall between the brush blades. Something has to secure the bottom together, and most vacuums have thick walls between which results in tiger stripes when you vacuum the floor. So with those you have to make multiple passes in order to get everything smooth and even. With the Oreck's it is done in one pass.