Originally Posted by Hitch
With regard to the ePUB, I prefer to make my own, over Calibre's coding. A lot.
Amen to that. Calibre's epub code, while valid, is not, shall we say, maintainer-friendly. Just fine for quick-and-dirty format shifting for personal use, though.
As for epub -> mobi via calibre, I find it more convenient most of the time to just use kindlegen.
(who is not a cat slave, but a cat senior staffer.)