To see the Kirby at its best you need a Kirby salesmen demonstrate it in your home, it's salesmenship at its best!
They pour salt & flour all over your carpet, grind it in with thier shoe
then they ask you to Vac it up with your existing vacuum cleaner
After you've done your best they do one pass over it with the Kirby,
When demenstrating the Kirby the salesmen fits a filter box to collect the dust instead of a bag, he then empties this filter into you hand to show you how much salt & flour your vac leaves behind..... its brilliant
Mike