I liked the movie. Not as good as I hoped it would be, but a more than worth ending to cap off the prequel trilogy.
The first hour or so started off slow--strange considering how action-packed it was. The space battle, touted as the "biggest in Star Wars history" seemed distant and unexciting. Return of the Jedi still gets the award for that. I think the reasons the space battle seemed boring were twofold--for one, there was no tension. We know that Anakin and Obi-wan have to survive the battle because they will inevitably end up in the classic trilogy. In Star Wars and Jedi, we knew the names of the characters that got zapped (Porkins! Biggs!) and feared for the lives of Lando and Wedge. In Sith, the battle consisted of Anakin, Obi-Wan, and expendable pawn clonetroopers. The other reason that the space battle suffered was that there was no cohesiveness. With the way some films are edited these days, including this particular part of the film (and the Clone Wars scenes in Attack), there is no general aim to the action other than "Blow stuff up, be background filler." In the Jedi battle and the Star Wars battle, there was a flow to the actions (i.e. attack the Death Star, switch to attacking the Star Destroyers because the shields are still up, shields go down, attack on Death Star).
Another thing that really threw me was the lack of score for the first half hour or so of the movie. For almost their entire assault on Grievous' cruiser (with the possibility of slight, short exceptions), Obi-wan and Anakin were not accompanied by Williams score (from the first battle droids to the Dooku duel to Grievous' bodyguards). The first five Star Wars movies were pretty much scored wall to wall, and it just didn't seem right to have no score whatsoever for such a long stretch of time. In addition, seeing the movie intensified the feeling that I had since I bought the score early this month--John Williams' score is really not very good. This is a general trend I've noticed in Williams' work in the past six years or so. With the occasional exception--both prior Star Wars prequels, the third Harry Potter, and AI Artificial Intelligence--Williams seems to be losing his touch (see The Patriot, the first Harry Potter, Catch Me If You Can, Minority Report, The Terminal). Even the inclusion of old themes from the original trilogy--the Force theme, the Imperial March, Leia's theme, the odd Yoda's or Emperor's theme here or there--couldn't save this uninspired score. Odd that it's uninspired, because this film, of the three prequels, seems to be the most well-rounded.
There were a couple of things in the flick that were just over-the-top goofy. One of those things was the way Palpatine acted before turning all wrinkly and old. While he was dueling Windu, he was making the most ridiculous faces and noises. Another thing was the aforementioned Vader scene. It would have been so much more poignant without the "NO!", but they probably paid James Earl Jones too much to let him get off with only forty seconds worth of work, so they added six minutes worth of "NO!" In fact, all of the James Earl Jones dialogue was bad. I know they had to add some semblance of similarity between the character of Vader and the character of Anakin, but the "Is Padme okay?" stuff didn't make sense coming out of the helmet of "more machine...than man, twisted and evil."
All of the concluding moments that wrapped up the film felt very Lord of the Rings-ish to me. After revealing what was going to happen to Leia and Luke onboard the ship, they should have flashed to the Star Destroyers (Vader and the Emperor) then Tatooine (Lars and Kenobi) and ended it. While seeing Alderaan was interesting, it didn't add anything. Oddly (to me anyway), the most moving part of the entire ending montage was Padme's funeral procession (which included Jar Jar, E1's Boss Nass, E2's Queen Jamillia, and a shot of Anakin's famous japor snippet necklace). It seemed like a fitting end to the prequel trilogy to see all of these elements come together. I was not truely moved by the final Tatooine sunset, but that may be because they spoiled that wrap-up in the E3 video game.
I could have done without Chewbacca. Even with the Wookiee planet, it seemed like an unnecessary tie-in to the original trilogy (see also: Greedo in E1's cut scenes, Boba Fett in E2, Tarkin at the end of E3) to have Yoda befriend Chewie. Thankfully, Lucas' original plan to have a young Han Solo running around Kashyyk basecamp was canned before it was even filmed.
Lucas still uses CGI to a fault. While other filmmakers use CGI only to create what's necessary, Lucas uses it as a crutch. I've warmed to the CGI Yoda, only because it would be more jarring to see him suddenly switch from a puppet to a flipping computer frog than seeing him that way the whole time.
Despite the fact that I have so many complaints, I liked this movie. A lot. I guess the reason I have so many nits to pick is that I wanted it to be perfect, and it came pretty close. When Episode I and II came out, I didn't bother going into the flaws this in-depth, because that would have taken six times longer. So, a quick list of things I loved: Palpatine's post-scarring performance; both of the final duels (Obi-Wan and Anakin; Yoda and Palpatine); Obi-Wan's last words to a burning Anakin; Order 66 and the decimation of the Jedi; actual show of emotion from the actors (especially Padme, Anakin, Obi-Wan, and, somehow, CGI Yoda).
All in all, an uneven flick just like Episodes I and II, although better paced and (slightly) visually better.