I have heard nothing but rave reviews about the Dyson vacuums. I work at Best Buy (and believe it or not, we do sell vacuums) and frequently the Dyson rep. comes to see us. From everything I've learned about the vacuum (without actually having one) it seems phenomenal. I love that you never have to buy bags or filters - most Dyson vacuums have two washable filters.
One of these days, when I get the money I'm getting one! :P