Did anyone notice on the YouTube engineering demonstration of Cinetic 'science' - when they were demonstrating "ten years worth of dust" (they used a white powder), the opening of the hose is unobstructed? Having no attachment (like a crevice tool) on the end of the hose, allows maximum airflow (and maximum separation). But in regular, normal use, the amount of air into the machine is constantly changing, as the tools are used. As the machine goes from carpet (sealing to the soleplate) to floors (no seal), the amount of airflow into the cyclones changes. This change effects how efficiently the cyclones can separate (and in the case of the red tips on the cinetic models - how fast they oscillate). I would have liked to see the engineering department test for 'ten years' worth of dust using attachments, restricting maximum air movement. As it would have to cope with dust in normal home use.