I scrimped and saved for a Dyson, found a refurbished one online for a great deal, bought it and have NEVER been sorry that I did. It's the best vacuum cleaner ever. It still works as well now as it did when we first purchased it and I'm completely in love with it.
I have old old worn out carpet. The way it works makes the carpet look just a tiny bit newer/better again which is ALWAYS a good thing. And it picked up so much stuff that our previous vacuums never did. Strange story - our black, long hair cat had been gone for about a year when I got the dyson. I had vacuumed faithfully. When we tried out the Dyson, there was so much of her hair in the canister, and other dirt that it picks up that conventional vacuums don't seem to be able to) that I went through 2 canisters in doing the house. And I vacuumed twice a week before so it's not like I hadn't vacuumed in three months.