Ex machina
Quite good. CLB took an episode I wasn't crazy about and a movie I didn't care for and made a really interesting story. There wasn't a ton of action, but I didn't miss it because of the excellent characterization. The introspective moments were great; I felt like I was learning new things about characters I've been watching for 30 years and all of it still felt natural. The dialog between the cast was also very good; it fleshed out the relationships between the crew at the time of TMP in a much better way than the movie itself did.
I have never been a big fan of the more "alien" of the alien crew that we get in a lot of books, but I think they were handled pretty well here. The various societal differences and modes of thought were well thought out and showed why each character joined SF while also demonstrating how their unique backgrounds made them valuable additions to the crew. I also like the fact that McCoy expressed his opinion about all of the practical problems inherent in a highly mixed crew.
The best part of the book imo, is the care taken to make each species and segment of society seem realistic. . The alien (crew members and Daran 5 denizens) are very different than the humans, but there is enough background detail about their home planets that their societies seem perfectly logical. But it isn't just the aliens who are treated this way - the religious and political groups on Daran IV aren't just given cookie cutter motivations. Each group is allowed to explain their differing opinions in ways that make their ideologies perfectly believable. Very well done.