That list is for upright vacum cleaners whereas the Vax & The Dyson are cylinder cleaners and that's a whole different debate, really.
I can't find a trace of 'Smart & Tested Top Tens at Amazon and various Google searches only bring up a dated 'Smart & Tested' page for GPS systems.
Plus, that list was compiled by one individual so it's likely to be either a personal opinion or greased by payola.
In the same way that many folk are victims of style over content some folk will believe any reviews/lists/opinions on the internet or magazines and trust in them. Fools. As an example, there are good reviews out there for Mesh computers.
I will agree the Dysons look good if you're into that kind of thing but as Amstrad and Bose were and are to the world of Hi Fi, so Dyson are to the world of Vacum cleaners.
In my opinion
I'm only quoting my experience here which is all I really trust. I've used Dysons before, last used one in a Mosque at Gravesend to hoover up some mess I'd made on the carpet installing CCTV. It was useless.
If folks are happy with their Dysons, so be it, who am I to criticise?