This is worth exactly what you pay for it. It's poorly laid out, with a very bare-bones look. Information seems culled from wikis, as there are numerous errors - at least as far as being up to date with fifth edition lore is concerned. The Sword Coast Adventurer's Guide has less information about each nation, but it's information is correct so if you see a contradiction between the two, go with SCAG. Another great source of information are the novels of Erin M. Evans: Ashes of the Tyrant and The Devil You Know. It's unfortunate the author of this work seems to have utilized sources summarizing Evans rather than getting details from her themselves, as the novels are very difficult to find these days due to short print runs, and are very long reads as well, so an accurate and detailed summary would be very helpful to anyone running a campaign in the Tymanther or Unther area. There's enough here to provide some inspiration for a DM who doesn't have any sourcebooks handy and can't access the very-flawed Forgotten Realms wiki, but as a good updating of the lore on these empires to a Post-Sundering world it's a shallow and oft-incorrect work. Good thing it's free!