I hate to chime in negative on this one, but a friend of mine bought one and has already had several things brake -- Dyson the Bose of vacuum cleaners. POS with a GREAT marketing department. If you vacuum alot, like my OCD wife, you need something serious. If you don't have kids and vacuum once, mabe twice a week, them it will probably be OK.
I'm an engineer and actually went to a place the had disected several models, the Dyson included. I can honestly say it is no better than most of the cheap ones out there on the inside (though the outside is nice!). For maybe a $100-$150 more I bought a Riccar. All metal construction, motor built like a brick outhouse etc -- a comercial-grade unit. It's all personal choice, budget etc., but I always like buying stuff for the long haul, it seems as cheap over the long run, but much greater utillity and less hassle.