I enjoyed the book. It's decent MilSF, with some good ideas implemented in ways I haven't seen them implemented before. But there are a few things here and there that I found jarring.
The first book ended on a cliffhanger. And this book started well after that cliffhanger had been resolved. This book also ends on a cliffhanger, and I have no doubt that the author will do exactly the same thing that was done with the previous book's cliffhanger: Ignore it and move forward in the storyline to get the book moving.
It's not at all clear how the simulations work. Transferring consciousness into another body isn't a new concept in MilSF, but it's not one that's been beat to death, either. But there's no comm lag between the sims and the "real" bodies of the characters. There are characters who could be several light-minutes away from their real bodies, and yet they die and wake up immediately. This was an issue in the first book, too. Also: Since comms attract the alien hostiles, how are peoples' consciousnesses being transferred back to their real bodies? Because clearly memories and perceptions from the sims are making it back into the real bodies.
The "good" faction of humans seems to be completely riddled with spies, traitors, and infiltrators. It's as though their internal security is completely worthless. In this one, it's a top-secret mission and one of the teams that is sent is made up entirely of traitors who were hand-picked by a member of the command staff. Not only that, but the villainous faction of humans is reported at several times to not be as advanced tech-wise as the good guys, but their sims are all "next-gen" or "second-gen" sims. IE: Better. Because they have completely infiltrated the SimOps program.
If you don't think too hard, the book is fun. It's a few hours burned, and has some interesting ideas. Just - seriously - don't think too hard when you're reading it or you'll get frustrated at more than what I've already shared.