We were looking at Dysons about 3 years ago but the sales guy did a few side by side demos with a bunch of models and ended up going with a Miele S6 Continuum instead (Vacuum Store on centre street North is great btw). It also helped that they had a promotion doubling the standard 5 year warranty to 10 years.
That said, our next vacuum we'll probably be looking into something cordless for convenience... will see what's available at that point but i've heard good things about the cordless Dysons.