I saw The Two Towers over the weekend. It's an impressive film, especially technologically. In that, it is superior to the first film. But unlike the first film, serious liberties are taken with the plot, in ways that mostly weaken and hurt it. Peter Jackson, who does seem to get Tolkien at least somewhat, has succumbed to the screenwriter's temptation: to "improve" something that does not need it.
Let me first praise a sequence that Jackson adapted very well: the fight between Gandalf and the Balrog. This brilliantly opened the movie. No "last time on..." for TTT, a good decision. The sequence itself depicts accurately what Tolkien wrote on it. And the special effects - the Balrog - are stunning. I want to see it again.
Gollum is a marvel. I noticed one time when he looked a little bit out of context. But other than that, I accepted all of his interactions with the background and his dialog with the hobbits. The dialog is especially important; the character must seem to "be there" else the other actors will appear to be having a dialog with someone just over his shoulder. But in TTT this was not a problem. And that allows the Frodo and Sam (and Gollum) some excellent opportunities to act.
When I reread LotR, I often skip the Frodo and Sam arc. But in the movie, I found myself wanting more.
I did not want, nor approve of, the liberty taken with Faramir. At least I think I understand the motive - to show the dangerous power of the ring. But yes, I get that. I got that last film, actually. Meanwhile, taking the Ring to Osgiliath is all wrong. Stumbling into a battle in progress there, wrong. Battles in LotR, and medieval fighting in general, is not WWII. The Rider seemed to know the Ring was there; that's wrong. If Sauron had had any clue who had it, he would have concentrated all force necessary to take it. Concealment, not revelation, is Tolkien's theme wrt the progress of the Ring. When Jackson departs from the book, he makes ugly mistakes. These were relatively small, but annoying.
More annoying is the partial stripping out of an important Tolkien theme: the necessity for men (and others) to think, judge, and act in the face of uncertainty. This is most clearly seen in the meeting of Aragorn with the Rohirrim. In the book, there is a hard decision that Eomer must make. He must judge the honor, truthfulness, etc of the Fellowship as against an impersonal law that no stranger may walk abroad in the Mark. He thinks, questions, and finally makes the decision. He says what he decides, and does it. In the movie, there is not. particularly much at stake, since Eomer is an outlaw. The decision seems to not mean much, if anything: some outlaws give up two extra horses to some other guys.
There are many other decisions that characters, major and minor, must make in the book. In the movie, everything happens as if foreordained.
In the book, the decision of Hama, the doorwarder of Theoden, is a real one: let in Gandalf with staff, or not? In the movie, this is played as a clever joke. Funny, yes, but then seemingly decided with no difficulty. Show me. Tell me. You can have the joke and a real decision.
In the book, the testing of Wormtongue is a real test. Theoden honestly wants him to show by deeds that he is true. You get the feeling, reading, that perhaps Grima might redeem himself in battle. The decision is real, and he chooses to leave. In the movie, he has no choice, and runs off.
In the book, Entmoot is a big deal. Ents meet. Hobbits testify. Ents testify and talk. Finally, decision is reached to attack, even though it is unentish. And attack they do. In the movie, the Ents decide to do nothing in entmoot. Treebeard has to be tricked into seeing some dead trees (and then all of the Ents just appear, as if they were going along for some odd reason). Lame. So what exactly did they talk about at Entmoot? The weather? Did no Ent think to look at the eastern edge of the forest to see how it fared near Isengard?
In the movie much is made in Helm's Deep of the "decision", such as it is, between despair and fighting on. In the book, the fight there is certainly real and interesting, but it is not about despair. Nobody, as I recall it, is showing signs of giving up hope.
So in summary, the movie's plot has been streamlined quite a bit from the book. Real, hard decisions are rarely made, at least, not onscreen. Instead we move from one happening to the next automatically. Decisions are made by Saruman.