From publisher blurb:
Diamond Polished Samsarans is the first of, hopefully, many additions to bolster and make certain races “live up to” their setting expectations, offer new mechanics, and other extended content. This book is for Pathfinder 1st edition and also provides support for a number of 3rd party systems, including from Drop Dead Studios (Spheres of Power, Spheres of Might, Spheres of Guile) and Dreamscarred Press (Path of War, Akashic Mysteries, and Ultimate Psionics).
Diamond Polished Samsarans reprints the samsaran race with a number of new changes, including new racial abilities and alternate racial abilities to help samsarans live up to their story and deepen their mechanical expression beyond a single racial ability. The content presented in this book is backwards compatible with the original samsaran race (i.e. feats and other options previously printed for samsarans are still valid for a samsaran using this ruleset).
This version of the samsaran race is meant to be on-par with the more commonly “powerful” race choices such as aasimar and tiefling, but also keep up with the other 3rd party support that many races have received over Pathfinder’s lifetime. The resulting design resembles something of a “build a race”, but from options that are meant to play well with each other and be roughly equivalent.