Like others, I've worn out heaven knows how many copies of the paperback novel, and often wondered how it would fare as a movie -- in the commentary, even the producers commented that prior to filming, it was the only epic novel that had never made it to the screen.
And they did a marvelous job, allowing for having to considerably compress the chronology of the story and to work around a major chunk of Rand's book being expository. Part 1 covers from the beginning to the igniting of "Wyatt's Torch", and does take some artistic liberties with the story-line ... in particular, it's not till much later in the book that the nature of the strike, and the fact that John Galt is a real character, are revealed.
My only gripe is with casting ... Matthew Marsden as James Taggart seemed horribly miscast. In the book he's, IIRC, a fair bit older than sister Dagny and a fairly strong, if relatively unprincipled, industry exec. In the film he comes across as not only acting wimpy and whiny, but even looks younger than Dagny. I understand that the *entire* cast was replaced for Part 2, due out later this year, and it'll be interesting to see how that changes things.
The maiden trip of the super-train, the first to run on Rearden Metal rails (and over an impressive-looking bridge of the same material) was one of the high points of the book, and is paid proper homage in the cinematography, as at least one other reviewer had noted.
Regardless of your socio-polico-economic leanings, this is a great film.