Some things work differently on TV and on books, and they changed things to make the storytelling better suited to TV. For example Camina Drummer was introduced much earlier in the TV series so that Fred Johnson had someone to talk to on screen, which wasn't needed in the novels. And then the character worked so well that they expanded it to cover more stuff.
I really like that they prefer a good story over sticking to the exact "canon" of the novels. And in "they" I include the novel authors, who are very involved in the TV series.
Don't get your hopes up too high; "The Expanse" is often nicknamed "The Expense" due to its high special effects budget. Amazon Prime may decide that later seasons need to have their budgets cut.
Game of Thrones did not have a budget problem for the last season; it had a writing problem. While other seasons used the novels for the build-up and for the story to make sense, the last season did not. And while the author does know where he wants to land, he hasn't worked out, or hasn't shared, how to get there completely yet. The tv show went there with no proper buildup, which is what makes that season poor. To me, the final situation, or who wins/dies, is not the problem, nor are the effects.
As for The Expanse, it's season not seasons; the next season will be the final season. I cannot see the tv series ending in the same end point as the final novel, that is I cannot see them cramming four novels with one huge time gap in between into one season. But I do believe it will come to a satisfactory conclusion at some alternative end point.
If the show runs into any problems it wont be because they ran out of source material and winged it like what happened with Game of Thrones. I doubt budget will be an issue since they've already wrapped filming the final season. The expense of The Expanse may be why its stopping where it is. But I have no reason to think the show wont end strong at this time.
After having watched all of the show released so far, I just finished Leviathan Wakes.
Maybe it's my fault for having mostly read Terry Pratchett and Douglas Adams for the last few years, but I found the writing to be extremely bland. It does the job of narrating the plot but the lack of all flavor would have turned me off immediately if I wasn't able to visualize the characters and scenes from the show.
That said, I'm pretty happy with the changes they made for the show. And a bit annoyed that most of the things I didn't really like about the characters were details carried over from the books.
I also found the series lacking humour, but maybe that's because I've only mostly watched Mock The Week and Have I Got News for You for the last few years.
I absolutely love how they changed "Ashford" in the books from an elitist obstructive middle manager into "Klaes Ashford" - legendary OPA member, space pirate and "The Ghost Knife of Callisto".
The show really gives the opportunity to explore the individual motivations of the characters; the books are also great and they complement each other, but I feel that the books are almost too fast paced to really savour the environment and setting.
That scene in the behemoth in s3e11 between camina and ashford is one my favourite. Their discussion of what it is that makes belters what they are in that situation, such great writing
I agree. I read the books after watching the first four seasons, and I felt disappointed how Ashford is described and handled in the books.
Also, the books set a very high bar for Naomi's "solo adventure" (let's call it that to prevent spoilers), and the series did such a great job, and stayed very true to the source. It was satisfying seeing this unravel almost exactly as I had imagined it.
The Cibola Burn book did a much better job of explaining things on Illus, particularly the alien stuff. And the Investigator POV chapters were wild. You don't get as much of that on the show.
For example, the story from Cibola Burn seemed a lot better on the show than the book in my opinion and some of the characters are better.
In particular, Ashford's character is massively improved (it helps that David Strathairn plays the role incredibly well).
The books are very good though and I can't wait for Leviathan Falls. Also, it seems the series will stop at the end of Babylon's Ashes.