The vacuum cleaner repairman in Dade City, FL said to avoid Dysons because parts were expensive and hard to get. So - I have no personal experience with them.
I like my bagless Hoovers, but I don't have the kind of carpet you are talking about.
They do a good job of getting the cat hair up. Mine are between five and 10 years old, but what I was not impressed with was the very short attachment hose.