Book 7 was a bit of a drag for me, more so than book 6. Books 8 and 9 are really fast paced and good. It's all proto molecule stuff. I remember not caring about the free navy and just wanting to get on with the larger series plot during 6 and 7. You may have to trudge through those to get to the good stuff though.
I randomly chose this to listen to on audible a couple months back; I loved it! So fun, so thought provoking, such a good book.