as the caretaker of 2 reformed feral cats, i bought this as a housewarming present for them, because moving them was traumatic. they took to it immediately, and after 3 days when i opened the door to their room to let them explore the rest of the house, they did not want to leave their castle! our 3rd cat is a bit sedentary and on the miss piggy side of the line, and she has been getting quite a workout to get to the upper reaches with the wild ones.  so maybe we can add weight loss benefits to the list of pros! overall, it was worth every penny!