Hello!
If this question should be elsewhere, I'll ask there.
I'm considering a Kindle Paperwhite to "replace" (but not throw away) my Kobo Touch. As the Kindles are all internal memory only, I've been playing around with Calibre and mobi conversions to see file sizes.
With my Amazon direct purchases, the original file sizes are smaller than when I run them through Calibre to rename and convert to the Paperwhite settings. When I run the same files thru to convert to epub - which makes the file sizes 1/2 that of the original mobis

- then back from epub to mobi, I still wind up with the same file size as I would if I were to do a direct convert from .azw mobis to calibre mobis.
Is there some way to tweak the converted files to either have them match the original Amazon file size, or even make them smaller than that? Space is an issue, and I am a hoarder.