Well, I picked up the book a couple weeks ago now and I can say what I have said over several Green Ronin products: I never feel Buyer's Remorse.
Much like Testament there is a real effort in this book to make a supplement that will both appeal to those who have a knowledge of the place and times and yet also appeal to gamers. You get enough information concerning the Golden Age of Piracy to have fun, but there is also a healthy does of Errol Flynn style swashbuckling, voodoo-inspired magic, and the like. Even on these two counts there is a strong nudge towards accuracy mixed in with the fun -- there are, for example, three duelling PrCs that are both very, very tasty (a rare commodity for most PrCs, in my book), but also very accurate, in that they reflect fencing styles of the era (one for the "Spanish" School, one for the "English" School, and one highly moldable PrC for the "Continental" School of swordplay). And the material on voodoo is not something drawn out of some 1930s shocker film; while it is not 100% accurate (and the authors are careful to point this out), it is much more in line with Santeria, Voudon, and Okunda than any other treatment I have seen to date.
The setting is very Low Magic (something I truly enjoy), but superstitions are everywhere.
There is a good amount of material on ship-to-ship combat (and, even more importantly, ship chases), as well as merchant routes and like treasure to be found in such prizes (you will be selling a lot of tobacco and grain, in all likelihood). There are also rules for your crews, with the double problem of running a pirate crew -- to be at their best, they should be sober, but if they are sober, they are much more likely to mutiny.
I could go on, but suffice it to say that if you are looking for material for a piratical or swashbuckling game, this book is fantastic; if you are not looking for that, you may still find very useful material within its covers.