Much more than I expected! I'm not sure what I think of astrology as a "science," but I'll tell you what, this book absolutely described me (through my sign) to a "T," and also correctly identified those I would get along with and those signs that would be disasters for me. Fun reading, and also helpful to produce more reflection on the part of gay men about who they're dating, how it's going, and why. Also very helpful is pairing up each sign with its 12 matches -- and doing this for each sign. For instance, it's helpful to match up Aries with Leo from the Aries perspective, and see how well it would work for the Aries partner. But it's also important to pair up Leo with Aries and see how it would feel from the Leo's perspective! Similar books, like Jill Dearman's Queer Astrology for Men, only match up the pairs once, in shorter sections, attempting to do both perspectives at once.
I have used this book for years and have found Michael Jay's descriptions of the signs infallible. I love to amaze people by having them read a section about themselves. EVERY time they say "oh my god, that's me!" The descriptions of the signs paired up is also very valuable whether for love or friendship. I can't recommend this book enough!