I've gone through the Extended Editions for the first two Hobbit films, and did not see any scene that was imperative to add. The scene with Gandalf calling out the dwarves for Beorn was kind of funny, but it just dragged on too long.
I'm definitely going to use the Extended cut of the third film, since it was obvious that much was left out of the theatrical version (Beorn, Dain, Bard, Thorin's burial, etc).