Rifts is a terrific setting, unfortunately shackled to the godawful Palladium RPG system.
There are lots of wonderful creatures and concepts, and I own dozens of the various sourcebooks. The Coalition States are developed in this book, along with a smattering of other nations. The character classes are very diverse and entertaining. But it can be a challenge to balance a party around characters like the Glitter Boy (can shoot through buildings), or a Dragon Hatchling (actual dragon and inherently an MDC creature) and a Rogue Scholar, whose special power is literacy.
The basic tenants of the combat system, and power creep since the first edition, also lead to either a slow combat consisting of whittling down the opponent's hit points/armor, or an over-reliance on called shots. When normal players have hundreds of hitpoints, and boss monsters have thousands or tens of thousands of hitpoints, someting seems a bit off-kilter.
I do recommend buying these books, but only as a sourcebook for other systems such as FATE, GURPS, or Hero with more rational mechanics.