I empty my DC07 every 2 weeks (as you can see from my avatar I just let it fill) and it usually lasts just over 2 full house cleans if I do the ground floor with the DC22 daily through the week then just once when I do the rest of the house with the DC07.
I empty the DC22 at least every 2-3 days using it everyday for the ground floor, even though its not full all the dirt builds up at the front passing the max line only at the front
Also has anyone else noticed the max line is getting lower and lower on newer dysons, the dc01 was huge, dc04 a bit lower, dc07 a bit lower and so on.. wierd.
Some people I know with older Dysons let it fill right up while others empty theirs after every use even if its not full. How often do you empty yours?