I agree with you guys on the pacing; I had never heard of the series until I started watching, but after seeing the first few episodes I blew through the first book.
The pacing is definitely a little surprising. In the first four episodes they go pretty quickly through the story, but then slowed down a ton in episodes five and six.
Random thoughts and light spoilers for the book.
I thought they would cover a lot more ground in episode 6. A lot of the changes they've made work alright, but I'm worried they're about to make some big changes. For example, there has been no mention of Eros yet. When they were talking about meeting up with Lionel Polaski "coordinates" were mentioned. Don't you think they would say station if they were going there?
So, my guess is the coordinates will lead straight to the Anubis? And then maybe they'll have an incident occur on Ceres instead of Eros to avoid needing to setup a new location and to keep some of the characters involved (Dawes, Muss etc.). Because I don't see any other way for Miller and Holden to meet up. Possibly just combine Star Helix and Protogen to save from having to develop another organization?
Another possibility is that the first season ends with the research station assault. Because I don't see how they can get through everything else in only 4 episodes.
Not sure where Avasarla fits in with everything either. Or the thing with the miner and his nephew.
Now, some of the changes I like a lot. There has been more mention of Phoebe, the Dawes backstory was really good, and the treatment of Holden seems better than the book. It helps to set him up as more of an idealist. However, really hoping they don't throw in a love triangle with Holden, Naomi, and Amos.
One change I don't like is that things occur much quicker in the show. In the books they talk about travel from places taking months. In the show it seems like everything just happens to be a day or two from everywhere else.