I'd forgotten about that show, the expanse, it's one of the best science fiction series i've seen in a long time apart from westworld which is excellent as well. 
i knew i liked miller but forgotten why, then i saw the scene that clinched it for me, the bit where he explains to his friend why he's on his mission. it's a great scene, they all have their moments, even one of the head people in the united nations is rich and interesting, in motivation and character. her voice sounds so expressive, iranian i think, she's amazing.
i think if you liked westworld you would like this, it's complex rich and well written.