I can certainly use the entities, but it is much more natural to use the actual character. My brain doesn't have to do the interpretation, and I'm all about doing things the lazy...errr...I mean...efficient way!
AFAIK, there is no need to use the entity...except of course for the "&". And I also remember someone mentioning that ePub3 doesn't allow the use of named entities, only the numerical code...
The saved search I have is just a click away and it transforms all of the entities. That....efficient...use of time is something I am willing to do!