Finally watched the special edition version that someone was kind enough to purchase for me. I thought it was more of an improvement over the original in some ways and less in other ways compared to the Fellowship special edition. For the first movie, the improvements mostly fleshed the existing narrative out and made for a much better movie over all. Nothing that was put back in was critical to the plot, but made for a movie which didn't feel like, as the theatrical version did, "battle... move... battle... move." The additions improved the pacing of the movie greatly.
The Two Towers special edition, on the other hand, does add back in some things which are rather important to understanding the basic narrative and the motivations of the characters - so in this way it's even more of an improvement over the original. But, I didn't feel that it improved the flow of the movie as was the case for the Fellowship. It didn't detract from it, but it still didn't feel as if the pace of the movie was ever quite right.
Still, definitely better than the theatrical version.
