Cat adores them, and they work
Ninja is fifteen and has been on these as treats for years now. The vet advised us to throw them for her as a game, and this includes throwing them to the top of her climbing wall (Phoebe posts plus a couple of little shelves) for her to climb after. She loves this so much that she requests it throughout the day, and will bite me if I don't do it fast enough!
She finally needed her first dental last Christmas, and had one tooth out. That's not bad at all for fourteen.