This is the first time I can remember that I've felt so disappointed at a Paizo product.
New content quality ranges from amazing to outright dysfunctionally broken . For every Green Knight Cavalier or Forester Hunter there's an utterly unplayable mess like Wilderness Warden or Nature-Bonded Magus. The "patch and reprint" policy is still going strong here, with a pretty good sized chunk of content being reprints. But most people don't care as much about that, so without further ado...
The Shifter Class sucks. It looks, both in design and formatting, like a playtest version of a proper class. The class seems to have started as some sort of Druid/Monk hybrid (cribbing a bit from the Hunter), and was just not developed from there. As it stands, the Shifter is inferior in the niche it seems to fill (shapeshifting themed beatstick) to Druids, Mooncursed Barbarians, Feral Shifters, and even Metamorph Alchemist. The archetypes, while flavorful, are sharply limited, when the entire draw of shapeshifting is flexibility and versatility.
That aside, there was some good content here. The expanded list of familiar and animal companion options is welcome (even with some reprints), the mundane/alchemical equipment is equal parts amusing and useful. Some of the archetypes are amazing.
Final Verdict: The book needs to go back in the figurative oven for a while, some of the content is still uncooked.