Can you outline the main differences?
I want to use one which someone else will be maintaining
so I guess that doesn't rule out either of them. I currently convert azw3 to epub before doing anything else. That won't change unless Amazon manage to kill off decent epub readers. I will definitely need to be able to access/update the actual html data contained in the html files and css data in the css file(s). Does that point me at one container rather than the other?