It immensely benefited me -- a web developer familiar with the craft but lacking depth. It could be a difficult introduction to read cover to cover! By all means get it if you plan a deep relationship with web programming.
No Starch Press is absolutely one of the best publishers in technology books, period.
Bill, their founder, also has a fine taste in scotch, so you should trust them based on that alone.
I've met the founder, Bill, he's a great guy.
It's the opposite of a practical security book, more philosophical I guess. A good read, full of more or less crazy ideas ..
