For the After the Bomb setting this book is pretty good. It has good spacecraft, some equipment, a solid setting, and the mutant insects of Mars alone make it worth the purchase.
For Rifts it has some OK power armors and robot vehicles but not much else for equipment and the spacecraft construction rules are much better suited for After the Bomb then Rifts. While the setting is still really good for Rifts, and is a great place to adventure, it is awfully limited, inner solar system only, and has no Occupational Character Classes of its own. However, it is a very interesting setting for Rifts and all the items that its missing just allow more flexibility for the GM.