Normally I like a nice, strong plot and focused driving narrative to my stories, and here I am giving a 5 star rating to a book that has virtually no story at all - It is, essentially, a series of character study vignettes of the crew aboard a small working spaceship, and how they interact and support each other. A lot of it is sci fi at its best in terms of using alien cultures as a window to view our own reactions and conflicts when dealing with other races, ethnicities, etc. It may sound like the sort of thing that could easily turn into a soapbox preaching finger-wag but it never does. Instead, the focus is enjoyably, consistently on the positive... It's not, "OMG teh racism!" but instead, "Hey, your species and ours are very different. How can we learn to respect each other and work together to achieve new things?" The affection and support that the various alien crew members show to each other is inspirational, warm, and just all-around fun to read - Despite not having a plot, per se, I never once got bored. The alien cultures are so well-written that I could easily have spent half the book on the planet of the lizard people, just observing their culture and ways of interacting with each other. 
 If you like your SF grim, gritty, or intense, this is not for you. It's an upbeat book about caring people doing their best to help each other get by in a difficult and cynical universe. I came away with a big smile on my face. Definitely recommended. 
 PS - It gets compared to Firefly a lot. It actually struck me as a mix of characters from Firefly and Enterprise, but completely without the Whedon-esque quipping and snark. This is a snark-free zone.