Re: Dyson have a point.
"Someone must define a 'standard carpet' with an exact laboratory-standard mixture of dust particles of various sizes and a measured quantity of cat hair."
Which? do this already. Here's a snippet from their 'How we test vacuum cleaners' notes:
"For our carpet test, first a machine spreads super-fine sand from Arizona over a carpet and grinds it in. We then strap each vacuum cleaner into the rig, which pulls and pushes it back and forth five times as it sucks up the dust. This is known as the ‘Arizona sand’ test.
We repeat this test several times, measuring when bags or canisters are empty, and also when they're filled with 100g and 400g of dust. Each vacuum cleaner covers a distance of 288m in this test alone. The rig springs into action again to do a similar job for smooth and creviced wood floors.
A bad vacuum cleaner picks up less than half of the dirt in the carpet, where as a Best Buy can pick up twice as much."
Miele usually spank all opposition.