Whilst I love the fact that there we get EEs for the Hobbit, I'm not sure that the extended scenes really improved the films in the same way they did for LotR. For me, watching the LotR theatrical films is weird, it's like watching an incomplete work. But I generally feel for the Hobbit there are scenes in the EEs that were rightly left on the cutting room floor.
AUJ is the best of the extended editions as the additional scenes are largely straight from the book(s) and really enrich the Middle Earth we see in the Hobbit. I think the extended and new scenes do improve the film, and add to the magic. I like 'Down in Goblin Town' and Thranduil's extra cameo the best.
I kind of wish I'd never seen the EE for DoS because most of the Laketown scenes are cringey and every single mention of Thrain is terrible. He should never have made
either cut, his new scenes are bad, and his addition to the prologue and Gandalf's investigation in Dol Guldor is really forced. On the flip side, my favourite scenes are, again the ones straight from the book, Gandalf tricking Beorn into letting the dwarves stay, and the stream scene in Mirkwood. I'm gutted that the filmmakers never completed the scene with Thranduil and Legolas talking about the fate of Middle Earth, because it would have been a fantastic addition. It would have also helped the high stakes in the battle in Bot5A seem less hokey too. But overall, I think I actually prefer the theatrical version of DoS, though really I'd like them to sell the Theatrical DVD in two parts, so I can watch disk 1 of the EE and disk 2 of the theatrical version!
With the exception of Dain's Coronation/ Thorins's funeral and Bilbo's honest burglar scenes, most of the scenes in Bot5A are kinda nice, but not necessary. The final scenes were great if albeit brief, I'm really glad we got to see them. I do wish we'd seen Thranduil at the funeral, got some closure for Bard's storyline and got a shot of Beorn walking back with Gandalf and Bilbo though. I find it odd that Bot5A has the most additional footage of the three films, but seems the least extended, maybe because they added quantity rather than quality. There's still scenes that develop the characters or round off storylines that I feel are missing. And I find it frustrating that extended scenes with Alfrid and double amputee troll which add nothing to the plot made the cut, when great character development scenes like
this scene with Thranduil & Gandalf were still left out. [The youtube link would probably be my favourite addition had it been left in btw]
In an ideal world, I'd like to cut my own version of the Hobbit, keeping some of the extended scenes and leaving some behind, but all that being said the EEs are always so much more than the additional scenes. I really do love the behind the scenes footage and how they show how the filming developed and unfolded, seeing the actors and crews antics is always a joy.