We've had the Dyson yellow for about a year (got ours on close-out from Home Depot for $249!!--they usually sell for over $400!)

. I love it on all our regular carpets. My one sticking point is on area rugs. We have a large area rug in our dining room under the table. The Dyson doesn't work well on it. You have to set it on the Bare Floor mode and it just won't pick up very well. If you set it on the Carpet mode it makes a horrible racket (meaning the belt turning appartus won't turn).
But for regular carpet the Dyson is the way to go.
And we have 1 cat presently (short hair tuxedo). We used to have 2 cats--one was a American longhair. When he shed it was like hair tumbleweeds everywhere!