What a wild ride! There is so much going on. Lots of threads here. If you haven't gone back and read some of the other stories like the Tyrus Rechs books, The Savage Wars, Dark Ops, etc. do yourself a favor and work your way through those storylines. Doing so will hugely impact the fun factor with this book, not that it isn't awesome enough on its own.
I've been reading some of their other stuff recently (Strange Company and The Forgotten Ruin series), but I was so very excited for more GE. It was worth the wait. KTF!