[Katsunami]

ATDrake, what is your reason to prefer an epub source? For me, it's only the fact that it's the default format, at the moment. I don't use (and even detest) any clouds, ecosystems and walled gardens.

I even keep a backup of all my original books outside of calibre. If I need more than one format in the future, say KF8, then I want to start from the same source, so: epub -> mobi, epub -> kf8, epub -> whatever. Or, mobi -> epub, mobi -> kf8, if the original book was a mobi. Making a chain of conversions between non-standard formats will be more risky.

Also I think that, because epub is the default, conversion from and to the format will be implemented faster and more accurately than conversion between two non-standard formats. I would not be surprised to see people doing mobi -> epub -> kf8 (or the other way around) before mobi -> kf8 becomes available.

Cwatkinsnash: I just want to keep rampant conversions from and to other formats in check.