Pros: convenient, easy to use, easy getting cat in, rolls with handle or turns into a backpack, lightweight, durable, mesh windows/vents
Cons: small space, not for cats over 18 lbs, slightly clumsy, expensive, no side pockets
After using those plastic carriers for years, I wanted to try something different. I found this rolling carrier on sale at my local pet store, so I thought, "Why not?" The material is a sturdy mesh, which is scratch-proof. It either rolls like luggage or it can become a backpack, which is very convenient. When rolling, there is a long handle to make it easy to transport. The wheels were a little clumsy though, and it was a little difficult to steer. When used as a backpack, it didn't quite fit my body frame. I'm only 5'1, so maybe the backpack is meant for a taller person. There are huge mesh vents on either side, so I don't feel uncomfortable about my cat overheating.
The space inside the carrier is slim. I have three cats, Buddha who is 18 lbs, Izzie who is 11 lbs, and Bowie who is 9 lbs. Izzie and Bowie fit perfectly inside, but Buddha had some trouble adjusting. Since it's not long and flat like other carriers, it's tall. The zippers were easy to unzip, which was a good and bad thing. Good because I could easily get one of the cats in and close the flap quickly; bad because once inside, the cat can maneuver its paw to open the flap. The carrier has this removable divider flap, but I don't use that because there's no way you can fit two cats inside without making them suffer. I wish it had convenient pockets for storing treats or extra food (or poop samples), like other carriers. For obvious reasons, I don't let my cat's head pop out of the front like the photo used for the review.
Overall, this is a great and convenient way to transport your cat. My cat doesn't mind being rolled to our destination, rather than being carried in a plastic carrier that bumps and moves side to side when I hold it. I haven't used it on an airplane yet, but I read that it was great to use while flying.