My hardcover from the Kickstarter came in a couple weeks ago. It's gorgeous. Though Pathfinder tables may want to be aware there are a lot of advanced firearms in here and you should be very familiar with how firearms work. Also make sure you double check a couple stat blocks I only found a couple hiccups mostly minor issues here and there. One thing that seems to make the most sense is that Firearms are treated as simple weapons in this setting as I saw a couple casters with Firearms as their primary weapons, but without the Exotic Weapon Proficiency feat for guns.
Now while that may seem like griping it's actually the only nitpicky thing I've had on it so far. I'm certain there may some small bumps here and there that may have come from developing both 4e and PF at the same time. I'm expecting them to be minor and I'm hoping to start my group on it once I hold Act: Two in my hands so I can have things fleshed out for foreshadowing.