The EE for TTT didn't quite make the miraculous difference for me that EE FOTR did , and I'm not really sure why that particular statement is true. It's odd how expectations change and evolve with the more that is revealed from the Peter Jackson movie productions. The additional scenes, all 43 minutes worth, are, in all fairness, very nice additions to the overall movie. I'm not sure that every single one adds something of significance to the storyline, but they were nice additions nonetheless.
But, really, how far will all of this go? Dare I even ask? Longtime Tolkien fans have had some very large pills to swallow since the Peter Jackson films began to be released; some of us have choked while others are still working on the "getting larger by the day" pile of said pills.
Read this nicely informative overview of the history of just how Peter Jackson's Lord of the Rings film made it to the silver screen.