Not sure if this has been discussed in similar detail before, but my recent investigation has proved to me at least, that using the new DRM-Free download option that Amazon provides, is generally not worth it ... unless they improve things ... or higher res images are present and worth it.
Here's my findings for one ebook -
Queen Of The Falconstar by
Joe Vasicek
Amazon
Kobo
Smashwords
DRM-Free and Free at all three stores.
AZW3 - 347 Kb - Acquired via an old Kindle device.
EPUB - 942 Kb - Acquired via Amazon's new DRM-Free download option.
EPUB - 281 Kb - Converted from the AZW3 by calibre.
EPUB - 643 Kb - Smashwords.
EPUB - 642 Kb - Kobo
Clearly there is added bloat in the DRM-Free download from Amazon. Plus chapters are missing indicators, so structure is not entirely correct. Author name is missing from metadata too, etc.
So why would you bother getting it using the DRM-Free download option from Amazon, unless you were some level of desperate, or wanted higher res images, if any. If you wanted chapter indicators restored, you'd have to spend time with something like the free Sigil editor or calibre's similar ebook editor.
File sizes were even worse for the following short story by the same author. Though admittedly we are only hugely better off with the converted to EPUB version.
A Hill On Which To Die
AZW3 - 205 Kb - Acquired via an old Kindle device.
EPUB - 1.12 Mb - Acquired via Amazon's new DRM-Free download option.
EPUB - 161 Kb - Converted from the AZW3 by calibre.
EPUB - 830 Kb - Smashwords.
EPUB - 830 Kb - Kobo.
So for my money, I'm just going to stick with the AZW3 and then convert to EPUB from that.