Ended up flying through the first season of 3 Body Problem. Excellent adaptation. A lot of changes among the main characters which work very well. In the books the protagonists are all in China, and making it more international does kind of make sense, but that aspect doesn't bother me too much, I'd have been equally happy with something more faithful in that regard. But making them a group of people who know each other, some of whom turn out to be protanogists and plot lines that are covered in the later books is a great way to adapt it. The main character from the first book doesn't exist in the show, his stuff is kind of spread across the group, especially Jin (who I quickly realised was Cheng Xin from the third book) and Augustina.*
Overall I really like the character adaptations. To be honest the characters in the books don't have a lot of personality and don't know each other, mostly the narrative is through what they're thinking, which wouldn't translate well on TV.
D&D doing a good job so far, and I'm somewhat hopeful by the fact that the rest of the book series actually exists. They seem very good at adapting but less good at original creation.
*SHOW SPOILER FOR ANY BOOK READERS NOT YET WATCHED IT ALL: I didn't twig that Saul Durand was Luo Ji from the second book until the very end. Even his meeting with Ye Wenjie didn't clue me in.