Do these kinds of containers work well? I always thought conventional wisdom was that they shouldn't be too small, but it would make sense that they prefer the smaller size.
It really isn't small, especially for only one cat. Might just look like it in this photo because the entrance isn't as big as the whole front of the container.
Sorry, should have been more specific. I remember that the cat should e.g. be able to stand upright in the carrier, though thinking about it a bigger space probably feels less safe to them. And since Miez still likes the carrier, it seems to be a good experience!