Whoo hoo! I can’t wait to read this book!
I had actually planned to read it after all of my Elixir/Phoenix books, however I’ve been increasingly curious about the Erlang way and how it differs to the Elixir way. @DevotionGeo’s thread here reignited some of that curiosity and Robert’s posts in the thread then just pushed me to do it!
I also purchased the paper book which is not something I would normally do for a programming book (I prefer reading eBooks on my Kindle and they are of course more environmentally friendly) however I thought having a physical copy of the book might nice, like having a little bit of Joe here 
Speaking of Joe, Like @Rainer I’ve only read the first couple of chapters but I can tell you Joe’s personality shines through very strongly. If you’ve watched any of his talks or interviews, or interacted with him via the forums, twitter or email, it’ll feel like he’s there with you. At least that’s how I feel given what I’ve read so far.
So I’m very excited to read this book and look forward to Rainer’s comments as well as any of yours should any of you join in or comment in the thread yourselves 