I can't review from a player or GM perspective, but you can't get much better than the latest revision to a time-tested system released under a truly fan-friendly open license for ten bucks. The entire text of the book, with the smallest possible exceptions, is open content; practically the only restriction is "please don't just sell reprints of the book" (an exaggeration, but barely). To me, that alone is worth the purchase price; this is a future-proof product that is designed to be used by players, authors, and game designers alike.