Has anybody experience with trunki? Good or just 'fun gadget' that one will never use?

We have a trunki. Its really fun for the kids and it actually helps you at the airport in case you want to checkin the stroller. With a trunki, you can pull rather than carry your child. However, the suitcase opens only one way and splits the body in half. That is slightly inconvenient when on the plane, since you have to lay it out. Its hard to open it inside the overhead compartment. All in all, I would say its nice to have but not a must have.