I really like the book. I prefer it to most any other "list o' creatures n' stuff" book there is, period. It is divided into understandable sections, and contains a lot of things you'd actually consider using. Normal people, for example.
If I have a pet peeve, it's with the Alien Technology(tm). Our star-faring nemeses, while holding the ability to apparently span vast distances of space to visit Earth, are doing so simply because their Plasma and Render and other guns suck to high heaven and they need to loot a few gun stores (assuming they can win the firefight there). These things are almost all heavier than normal firearms, and have immensely shorter range increments, vastly smaller ammunition capacities, and deal damage that is right on par, generally, with a typical firearm.
The way they stand, you should really be more afraid if an alien picks up an M-16 than if they use their Alien Technology(tm) on you. There are a few exceptions (some of their armor is very interesting and I think the Greys/Fraal have at least *one* interesting weapon), but for the most part the Alien Guns are pretty terrible, and certainly not worth training in their use (requiring a special feat) though that's a secondary matter compared to the fear that should be felt from having one aimed at you.
But it's a small matter. All in all, I still am very pleased with the book.
