I was a beta reader for this, and got a free copy of the final version, too. And there will be spoilers ahead for Torchship.
For instance, that ever since that Fusion ship dropped an atom bomb on a Disconnect world, there have not been good relations between Fusion and the Disconnected Worlds. The crew of Full Fives have to soldier on as best they can. Which involves a high-stakes ambassadorial mission with a ball, the return of a character from the ship last book, a renaming, meeting the parents after the wedding, espionage and a three-sided war, and more.
Also more history of the Betrayal. I particularly recommend this to computer programmers, who will like the history revealed here.