IM Richard Palliser is an excellent author, arguably the best at Everyman Chess. His works are always thorough and his recommendations always solid.
The author includes some explanatory material and gives justification for the lines that he recommends, but this book is more on the "database dump" side of the opening book spectrum. I must admit to being a little disappointed by this, having loved his Play 1.d4!, which I think is a repertoire masterpiece--if not for the lines themselves then for the mix of breadth, depth, and prose.
It could be said, however, that the subject is the Sicilian Defense, and any serious book with this topic must be very concrete. While that is true, I would have liked more practical (middlegame!) advice in the vein of Play 1.d4 or especially in the vein of The Sharpest Sicilian. It is this practical middlegame advice that, to me, places the latter work on a very short list of the greatest opening works ever.
Still, I think this is the best book on the Anti-Sicilians currently available. Recommended. Note well that this book basically deals with White second moves and, as Mr. Snow pointed out in his review, does not cover 3.Bb5(+) (the Moscow/Rossolimo Variations), for example, or Yudasin's favorite 3.Bc4. He does cover Zvjagintsev's 2.Na3!?, though with such a move there is much more scope to just "play chess" than in most other lines.