There are pros and cons to both. Cat backpacks are a compact size that is easy to move around with. However, it can be a bumpier ride for your kitty, as it will move with your steps. Though if you're wanting to find a carrier to take your cat to see the great outdoors, meaning hill climbing and rough terrain, it can certainly be the better option. Alternatively, cat strollers are a more smooth, comfortable mode of transport for your cat if your regular walk route is over relatively even ground.