I use Eudora on a fairly regular basis because I have to ;-)).
Personally I find it to be a bit of a pig and I would rather use Outlook or OE. Eudora has little extra 'features' that maker life easier and any that it does have are ones that you would only use once every blue moon. I find it somewhat coonfusing but then I am used to OE and Outlook.
Given the choice I would stick to OE or Outlook, they have more features than any sane person would ever need.