This is the book that takes D&D 3.5's Expanded Psionics Handbook and upgrades it to Pathfinder. That being said, that is all this book does. The authors do a massive job cleaning up the rules from 3.5's XPH and adding "0th-level powers" to the Psion and Psychic Warrior. The Soulknife gets more blade options than a bishojoen girls' anime. The Wilder now has "bloodline-like" options to their wild surge.
However, anyone looking for a collection of "The Mind's Eye" taken to Pathfinder or corrections to the Complete Psionic is not going to find them in this book. While Sorcerers, Wizards, and Clerics get a variety of "0th-level" cantrips and osirions, the Psion gets two. That's it, and there is no psionic feat to correct this deficiency. Pathfinder's Core book and Advanced Player's Guide has been taking feats from the prestige classes and adding them to the general populace. Psionics Unleashed does not do that. The races and monsters are translated to Pathfinder, with the addition of one Open License race. Some powers have been streamlined, while others (Metamorphosis) has three, not two, types. Prestige classes are upgraded without many changes to the Pathfinder system.
The one glaring problem is the authors' dependency upon the Psionics/Magic Transparency rule, such that most psionic skills and item creation feats were merged with their Core equivalent. This saves GMs and players a lot of headaches, but goes against the entire point of being psionic in the first place, in my own opinion. Imprinting a stone for a power is just as expensive as writing a scroll, for instance.
Psionics Unleashed does what it says it was going to do - it translates the Expanded Psionics Handbook to Pathfinder rules. Players will still need a stack of Mind's Eye printouts and hashed-out agreements with the GM to play psionics at all levels. Players with solo psionics in a group will have to become artificers just for themselves to get power stones, cognizance crystals, tattoos, djores, etc.
Astral Construct, which was viciously nerfed in Complete Psionic, is back to the old rules in the XPH. But nothing is brought forth to address making the Shaper more like the Sorcerer, with an Astral Servant, Astral Mount, Call Item, etc. Those are still Mind's Eye additions or homebrew solutions.
So Psionics Unleashed is worth the money ($10/PDF, $25/book at the time of this writing), but it's not a solve-all solution to psionics in Pathfinder.
