I use these for storage and also for transport to shows. They are padded, though not very thickly, and will prevent your drums from taking scratches and serious knocks.
If you need to ship your drums in the cargo hold of a ferry or plane where you can't personally keep an eye on them, then I would have more confidence in hard cases.
However, if you need to transport drums to a show in the backseat of a car, these bags are perfect. It's a plus that they can fold down when empty, so you can tuck them away backstage or in the corner of a room.