I admit to being a "Voyages of Sinbad" nut. That helps make this one of my all-time favorite RPG supplaments.
The voyage begins with a quest for the "ultimate treasure". The authors then discuss different styles of role-playing, and what makes an "ultimate treasure" for each of the different type of players. I've used the player-type guidelines to help shape my games for decades.
The islands themselves are well thought out, but most important, the authors never forget that this is for a role-playing game, and so every island and location is rich in adventures appropriate to player characters. I used many of these islands and locations when running a fantasy earth campaign (using Runequest rules). They fit beautifully.
The physical information on arabian-style ships is thorough, and the rules for trading and the merchant life are nicely detailed, and well balanced (another rarity).
Okay - I'm a fan.