@SampleAndy: We're not quite sure how/when Amazon backups collections on eInk devices, so, yeah, the 'Import from another device' feature can seem a bit wonky, at times. You might have better success using K4PC/K4Mac as the 'source' (or not, never played with that

).
If you simply want to 'clone' collections from/to a non-touch (K2/3/4) Kindle, if both use the exact same content (meaning same metadata/exact same path for sideloaded content), you can simply copy the collections.json file from one to the other. A restart later on the target device, and voilą

.
That said, I'm (like a good deal of people), personally using this fantastic
Calibre plugin, so I can't speak for any other tools

.