Before you commit yourself to read this humongous 1200 pages book, my sincere advice to you is to read AR "anthem"(her masterpiece), which is only 80 pages long so you can get an idea what her philosophy of objectivism stand for.
Her philosophy defined man as a heroic being whose sole purpose in life is to attain his own happiness, but at the same time no one achieve happiness by wishful thinking or whining for it nor by losing his moral integrity or respect for fellow human beings rights, it requires looking at the world from a rational view point. Her philosophy is so misunderstood that people criticized her by call her philosophy a philosophy of selfishness
Now coming back to atlas shrugged, I believe you can actually tell when a writer is in love with his work and characters, it just shows, plot and writing style is absolutely beautiful, each character is not picked from some fairytale, hence you can relate to them is some way. The perspective and depth of characters is depicted so beautifully. Even a simple act of smoking is defined so beautifully that you wants to read it again n again.
Philosophy and characters shows a deep understanding of human behaviour, but at same time lacks practicality in real life and at places it feels author is trying to shove her idea down your throat, AR had took lot of heat because of her virtue of selfishness. My advice is to read this novel without getting attach to any single character, otherwise you will lose the complete point.A MUST READ.