Generally speaking. Low end of mediocrity, initial throw away references. It's was like they got access to the entire Halo universe, but the story writers only played multi-player, read half hearted cliff notes, and tried to make up a story.
It's fairly disheartening.
In short, if you played any of Halos story and remembered/were invested any of it, don't watch it.
If you have no idea about halo, and want background noise this may fill it.