This a great product if you don't own the recent Alien module or guide - Zhodani. Ziafrplians Sector is exact copy of the worlds section of "Zhodani" including the illustrations. The product gives reasonable detail on 2-3 worlds in each subsector. I would have liked whole detail of worlds in subsector next to the Spinward Marches subsector. The other weakness of this product is it lacks a contents and index, which is poor considering the standards usually set by Mongoose.
I recommend it if only you don't own "Zhodani" or don't have any intention of buying "Zhodani".