Once again, I need to agree with Tolkien's warning that these are not separate books. This is clearly the conclusion of the story and this volume starts at the peak of action.
I think the most surprising thing in this volume was the bit of feminism in Eowyn's character. First we see her fight with Aragorn in an attempt to go with to war. She is dressed as a Rider and says that her fear is "A cage...to stay behind bars, until use and old age accept them and all chance of doing great deeds is gone beyond recall or desire." Later, of course, she sneaks into battle and is brave enough to stand up to the Nazgul in defending Thoeden.
I thought the pyre of Denethor (and attempt on Faramir) was a bit melodramatic and unnecessary; although it was a nice parallel to all the in-fighting with the orcs. I might have complained if there hadn't been any fighting among the heros, so at least there is that balance.
The scene in LOR #2 when Frodo and Sam look down upon the gates (prior to going around to Cirith Ungol) and again in Cirith Ungol when they dress as Orcs reminded me of the Wizard of Oz when the heros are sneaking into the Wicked Witch of the West's castle and dress as her foot soliders. Certainly many other stories have used this device, but for some reason the image of them hiding behind a wall watching the marching orcs and again dressing as them an then walking in step along the road later kept bringing Oz to mind.
I did not remember all of the details after the climax. I was surprised at how relatively quickly Frodo scales the mountain (in terms of this volume) and then the amount of novel left to wrap things up. I did not remember the scouring of the shire at all, but really liked that the hobbits did not return to an idyll and instead had to work at repairing Saurman's damage.
In all, the Trilogy is an amazing piece of detailed work. I was a bit bored at times (the fighting scenes and the excessive natural descriptions were too much), but it is definitely worth reading. I would say that if the Hobbit is good for 10-12 year olds, this is best for 11-15 year olds. I am not convinced that it is an adult novel.