I would 100% recommend the book series.
There are some differences from the TV series. The TV show combined some characters from the books and the deaths of some characters are materially different than in the books. The death of
in the TV series was driven by outside factors and differs greatly from the books.
The other key part is the TV show ended before some significant changes in The Expanse universe timeline. The show sets up a few plot points that will pay off in the book series that are just left hanging in the TV series.
I know there are some mixed opinions on the series after the in-universe timeline jump, but I happened to like it.
Anyway, the short answer is that I would 100% recommend the books or any fans of hard SciFi.
Valete,
JohnS