In my humble, but correct, view the theatrical releases are superior for two reasons: pacing and music.
First, the pacing of the extended editions is thrown way off by the insertion of the additional scenes. Yes, as a geek I am intrigued by the gifts given to the Fellowship by Lady Galadriel. I am also interested to hear about how the Ent men have lost track of the Ent women. And the added scene where we learn about Aragon’s extended lifespan gives the viewer a little bit of insight into why the character is so wise. All of these things are very interesting, but they do little to enhance the story or the characters. Worse, they actually minimize the dramatic tension of the story, which causes the pacing of the film to slow down. The theatrical version of these films moves along at a fast pace. The extended version drags on.
Second, the music of the extended edition hurts the overall story. I know that Howard Shore re-scored the extended edition, but the music just isn’t as dramatic in this version of the film. And this is not a poor refection on Shore’s brilliance, but rather the impossibility of coming back to a scene that has had an additional four seconds of content inserted and trying to make up music to fit into that moment while flowing into the rest of the score. It just can’t happen well. If you have both versions of the trilogy, go back and watch Boromir’s heroic last stand in The Fellowship of the Ring. The new music deflates the scene in the extended edition when compared to the theatrical cut. And this was done so we could see a couple extra Uruk-hai get their heads chopped off. Even worse is Gandalf’s glorious appearance at the Battle of Helm’s Deep in The Two Towers. The pacing of the scene is brilliant in the theatrical release. In the extended cut, the pacing and the music both hurt the dramatic tension.
More is not always better. I, for instance, could probably preach for four hours every Sunday if I wanted to. I put that much work into my sermons. But I boil them down to thirty to forty minutes. I cut out everything but the best content, and keep only the content that is of the most importance and I leave all the tangents on the cutting room floor. The result is a more enjoyable sermon. More is not always better.