Read through the whole thing. Really liked it. It's different than I thought, and in my opinion miles better than anything Jim's written before. My only real gripe with 5/3/1 before was that he seemed a bit tentative about it, and as a result a lot of people used it like pussies. This time around he focuses more on people with greater training experience and strength already under their belts.
Instead of just hitting the required reps or maybe going for a rep max or maybe going for heavy singles sometimes; he is much more about hitting rep PR's every time AND going for heavy singles AND doing drop down sets. Fuck yes. That's what I'm talkin about. I had already adapted my own version of 5/3/1 to be pretty similar to this, because I love training hard, but there were definitely things in the book I was able to immediately take and implement in my own program, especially what he calls "Joker Sets", which I found very cool.
As far as the "Beyond 5/3/1" part, this is actually an entirely new training program. I had no idea he was going to do that. It has similarities to 5/3/1 obviously, and his principals are the same, but it is much more of a circa-max centric program than 5/3/1.
So it's two main programs; his latest iteration of 5/3/1 and the "Beyond" program. There are many variations on each listed as well. Now despite the fact that this Beyond program is his newest creation, in all honesty I think I'll stick with just the 5/3/1. I absolutely love his take on 5/3/1 in this book; it's got literally everything I want in a training method.
Well worth the buy imo.