When I read something that isn't quite working for me, I always try to figure out what the author(s) found interesting about the story. For this particular book, for the life of me, I couldn't figure it out. It's a military science fiction book that doesn't seem to care about the science, the tactical or strategic combat, or the characters, so what's left?
The pacing was also a touch questionable with some significant story threads introduced late in the book. I assumed these might be hooks for later entries in the series, but no, they're pretty much resolved by the end of things.
Granted, a lot of this might be my fault for popping into the series so late, but there's a fair amount of recapping that would probably feel excessive for the long-time readers, so I never felt confused by what was going on just by why I should be too bothered about it.