I must preface this with a bias warning. I want my "campaign setting" books to be detailed. I'm one who desire more information rather than less. I prefer my books to detail locales. I also like having things statted out and concrete, so that I know that when I speak of an NPC or location, both the players and I know that we're on the same page. Realize that if you are one who appreciate minimality for the purposes of artistic freedom, or who disagrees with me on any of these points, you probably would find your opinion of the book to be quite different. Now, onto the review.
Introduction
I find myself disliking the introduction. It draws upon the history of the Realms, yet a great degree of it's history seems to have recently changed. The 10 important facts about the FR seem contrived. Three deal with the spellplague, two deal with countries that were already threats and explains why they're threats now, and one handwaives why there's no longer about 10 species of elves. All-in-all, not really what I might consider important facts.
Chapter 1: Races
This chapter contains four sections: A two page section on the Drow, a three page section on Genasi, a seven page look at Other Common Races (the races which appear in the Players Handbook), and a Supporting Cast section (involving Gnomes, Goblins, Orks and other races you might meet in game). I find this section lacking in depth. In the PGtF (3.5), we met Faerunian flavored races from the PHB. Gold dwarves, Sun Elves, and Ghostfoot Halflings, for example. I feel that omitting these makes the Realms substancially smaller. No longer is there as much diversity as there was before. I realize that simply making a Dwarf and calling him a Gold Dwarf is a possibility, but I do like having a standardized reference which tells me what skills and special abilities they might have that are different than normal Dwarves. As a corellary, there is little attention payed to races previously described in the PHB.
Chapter 2: Character Classes
This chapter explains the Swordmages, Warlock (Dark Pact), and Spellscarred classes in the same fashion as the PHB describes other base classes. It goes on to describe Paragon Paths and even a new epic Destiny. Not much to say about it, good or bad. I suppose it strongly depends on wether you care for the classes or not.
Chapter 3: Backgrounds
This chapter expounds on places your character may have originated from. The Guide goes into some detail about the places, enough for you to get a taste of where you're from and even offers some possible motivations! It's not a bad section.. except... it's missing certain places where I think it might be normal for PC's to begin from. Sadly, I believe that they "saved" these for Dungeons and Dragons: Insider articles, so I feel a bit swindled for not getting those places. One other nitpick, I really liked the tables from the previous edition showing, at a glance, a location, what bonuses you might get from coming from there, and what available races are there, which is missing from this edition.
Chapter 4: Feats
A chapter of new feats! However, unlike the previous edition most of it's feats are almost exclusively made for new races/classes which debut in this book. I suppose most of this chapters' draw will be wether or not you care for the feats.
Chapter 5: Rituals
25 new Rituals of varying enjoyment. Use to taste, some seem pretty neat.
Chapter 6: Almanac
A chapter which claims to cover Deities of Toril, Lore of the Land, The Calender of Harptos, The Roll of Years, Languages, Coin and Commerce, Class and Station, Families, Learning, Adventurers, The Spellplague and Cosmology. It seems like it's chok-full of information, but that is slightly misleading as it is only 10 pages long. The Deities have been cut down dramatically (one part which I dislike), and it seems that some of the sections are page fillers. Do we need entire sections on how there are different classes, how families are generally like how they are in real life, how there's not too many formal schools in Faerun and explaining how not everyone you meet is an adventurer? The Spellplague section manages to tell you of the Spellplague without actually telling you about the Spellplague.
In the end it feels like it's a low page count, large text-size, picture heavy pamphlet that is supposed to direct you to the ACTUAL Players Guide to Faerun. I feel like if I mixed this book with the Campaign Setting and the Grand History of the Realms, I might have gotten a full books' worth, but for now, I just have a feeling of emptiness, of not knowing, and of not actually playing in the Forgotten Realms.