As you can see, ncdt adds the size of files and directories as part of its default display. So in situations where it’s useful to see directory structure and size — such as labeling removable media, like CDs — it is probably more useful.
Unfortunately, I see no options to adjust what ncdt shows, so there are no “human-readable” (which I prefer) output flags or the like. What you see is what you get.
ncdt also promises to show “special” data for mp3 files, but the Debian version as well as the version I built on my Arch system from the Debian source package showed nothing. Even the sample screenshot in Debian doesn’t show anything “special” for mp3 files. Hmmm. 😦
It’s possible that there is an added dependency that I don’t have, or perhaps the mp3 files I tried post-date what ncdt is capable of analyzing. I checked the ReadMe and source files, but I got no hints. And the only home page I have for ncdt is the Debian package page above.
No matter. ncdt adds a little to the tree model and could probably, at one time in the past, show a little information about mp3 files. It’s an interesting evolution, even if it still needs some attention to reach fruition.