I use XMM8, and it's very good with movies, but it's worse than the older versions with tv shows episode info. I use imdb.com (tv series) script). It doesn't import cast and crew, only from main page, and if I add an actor/actress manually to an episode, it doesn't appear on the actor/actress page.
The import issue could be script error, but the other is not. I tried tvdb.org also, but as far as I know tvdb doesn't have too much info about cast per episode.