The Expanse has nice sets and FX, but is otherwise forgettable.
They're relying upon sterotypes instead of plot and characterization. Not impressed by the acting or dialog. Literally "forgettable." As in 10 minutes after watching an episode I have to work to remember anything that occurred in it and 3 episodes in I have yet to recall any characters' names. Nothing to get a viewer invested in anything on the screen.
Could be good. Needs a pro to go over the script and a decent director. Maybe they'll have a mid-season turnaround.