The reviews here are all pretty much one way or another. Most readers seem to like Science and Health, while many others have some strong negative comments/reviews. It should be addressed here, however, that many reviews are about the Christian Science Church rather than the book itself.
Some individuals have had negative experiences with the Church/religion, and while their experiences are certainly valid, I am not about to defend the shortcomings of a human institution in this space. I do feel the need, however, to distinguish between a religion and its book. People, for example, may have had problems with the Catholic faith in their life, but that's no reason to start bashing the Bible or giving it a one-star rating.
What few seem to discuss here is the book's central thesis, that God exists and that His divine laws should be directly applicable to us in our daily lives. I personally happen to agree with this statement, but I can also understand why some out there would disagree. Maybe they don't believe in God, or don't believe in Jesus' teachings. Maybe they don't think that God can affect their daily lives.
There are 100 pages of testimonials of people who were healed of various ailments from reading this book. Will your life be permanently changed by reading this book? It could. At the very least, you will read a book that makes you think about your personal relationship with God. For me, that's something that is without price.