We have the Dyson animal and I highly recommend it. I did my own little "test" when I first brought it home.
I vacuumed the rug in the office using my old cleaner. Then, I did it again with the Dyson animal. Not kidding here - canister was one quarter full!
For a pet household, or anyone with allergies, I would very highly recommend it. Very pricy, of course, but worth it. I kind of held my nose and told myself it should last at least ten years - didn't seem so awful that way.
Kathy