We have a Dyson Animal (the purple one) and really like it. As far as store-bought ones go, it's the one we liked best. We managed to use a 20% off coupon for Linens & Things several years ago before they quit accepting them for Dyson, so ours was only $400. It seems to do a great job at picking up the dog hair (we have a HAIRY golden retriever that I swear is part wookie)...when we get around to it, that is! :) I will say that we had a cleaning lady for a few months after my C-section, and she loves her Oreck. It was more basic, but she loved that it was light and compact.
We, too, had a Kirby demonstration at our house. I'm embarrased to say that as much as I love my Dyson, the Kirby put it to shame! But at $1100 (including the $500 Dyson trade in), I was not prepared to spend that much on a vacuum. If you can get a great deal on one, they are amazing machines.