This, like many of Ayn Rand's works, seems to be one of those "love it or hate it" books that has a very loyal following as well as many opponents. I don't think it's that easy because this is a very mixed collection of essays.
Much of the ideas presented in the first few essays are good and should be truly thought provoking for most readers. I have come to regard selfishness (though I prefer the term "egosim") in a new light, which has been good for me.
But here are also many flaws. Most of these are due to the utopian ideas in the essays. There seems to be no place for sick and unable people in Rand's perfect society. Based on my own self interest, I want a society that takes care of their sick and poor, because I would like to be helped if I got in that situation.
Rand's worldview is an oversimplified version of reality. She seems to believe in the libertairian myth that all men have equal chances in life to pursue their ambitions. She writes that one can only achieve one's goals through one's own effort. Never mind that some people (such as the heroes Dagny Taggart and Hank Rearden in her novel "Atlas Shrugged") are born wealthy while some people have to work full time just to feed themselves, not leaving much spare time to pursue their true ambitions.
Rand is so rabidly opposed to all forms of altruism she goes to the extremes to demonize it. This is another proof of her oversimplified worldview which leads me to the next point, how proudly she declares that she's an extremist. This is the essay titled "The Cult of Moral Grayness", in which she explains that it is evil to combine ideas from different philosophies and that the world must only be viewed in black and white, in terms of absolute good and absolute evil, with no shades of gray. My only interpretation of this is that Rand - Objectivism being the only rational philosophy - is always right about everything and if you disagree with her on any issue you are morally corrupt and evil. Thus, you must accept all of her teachings without questioning. In reality this means you are not allowed to think for yourself and evaluate them critically. This blind obedience is not compatible with rationalism and individualism. On the contrary, this demands you to stop think for yourself, out of fear that you may reach some "incorrect" conclusion that only a corrupt and evil person could do, which is exactly the sort of rethorics she opposes in the essay titled "The Argument from Intimidation".
It is quite sad that some of the essays express a very old fashioned and uninformed attitude towards homosexuality.
Although I found much of the rethorics flawed, I am glad I read the book, first of all because I did find good ideas in the first three essays, and secondly for the simple reason that it gave me a good insight of Rand's way of thinking, and it's always valuable to get exposed to different ideas in order to keep an open mind. Only after you've read something can you decide whether you agree with it or not. For these reasons I recommend this book. If you read it with a critical mind, it has some good ideas to offer, but don't automatically swallow the whole package just becase you agree with some of it. Be rational.