A Decent Introduction to Character Generation, Skills, Combat and Combat related Items. The Text is utilitarian and the Graphics are few, leading the book to appear very dense but, the book does give a decent overview of the game mechanics although not much into the setting. Of course, as an introduction, each section is abridged (for example, there are only a few of the careers available in the Core Rule Book). It is probably enough for a decent GM to craft a basic combat encounter or one-shot, however, I doubt it would be very deep. I used it to see if my group and I would like the game before purchasing the full edition. I suppose it would also be good for new players as a quick reference for CharGen/Skill/Combat but, If you're buying the PDF, it's probably cheaper to make copies of those sections from your Core book and lend them to players.
All in all, it is a decent product, however It would be more suited as a free demo from Moongoose than paid partial rule book.