It would be nice a graphics representation of sizes of folders. A progress bar showing the sized of folders and sorting by them.
Smaller footprint, the use of indexes and caching for faster accsess times and lower CPU and RAM.
If the disk is in overlaod (when copying a dvd or downloading large files from the internet then folder size should run in an idle mode)
A statistics option to export in plaint text or CSV whatever the user is interested in (size of folder, size on disk of folder, percentage of space on disk used by folder, etc...)
That's about it. Hope it's not much :D
Take care and thank you for this.........