This film was substantially better than I expected it to be, based on early reviews of it which mostly said that it's another brainless-but-beautiful sci-fi action flick. I am a big fan of the original 'Tron' and I honestly think this new one is better, and not just the special effects. I don't go see sci-fi action seeking great emotional depth or major intellectual challenge, but I do want to be immersed in a world I'm unfamiliar with and see some amazing sights, and not be treated like an idiot while I'm watching, and I believe 'Tron: Legacy' did an excellent job of this.
The computer-world scenes are extremely well-done; the new 'disc' and 'bike' scenes are totally killer, and the Recognizers are even more ominous than they were in '82. The story and script are good enough that I didn't detect any serious holes, the acting is better than I expected (though Jeff Bridges of course is always good), and I thought it was paced distinctly better than the original. Actors are way better at doing this type of film (doing all their acting in front of a green-screen) than they were in 1982 and the performances are not as 'stagey' as in the first film. Some reviews have said the technological ideas addressed by the script are 'passé', but I don't think the audience needs to take a computer class just to enjoy a film.