Brought one of the these other day from Amazon, at that was the cheapest place. I wanted a motor head to replace a DC05 'Turbo Brush'.
The DC21 is small and easy to carry around, although is heavier compared to older models. The hose attachment is badly designed for general use. You cannot break it down to get the nozzle into small areas, so won't be able to use this in a car. The Motor head itself is also massive, so it won't go under sofas etc, like the old Turbo Brush would. The Motor head is also really too big to use on stairs, but a hard floor attachment is provided, so you you can use that instead.
If the hose was detachable from the lance, this would be a much better product.