I just watched the first episode on Hulu. I don’t think I have any spoilers, but...
The opening sequence seemed more based on the previous movie than the book.
There’s more racial diversity.
Samira Wiley is her delightful self.
The Commander and Serena Joy are too young and attractive. This changes the dynamic of Serena Joy’s hostility towards Offred and SJ doesn’t say the “It’s one of the things we fought for” line, which I think is important to her character. She’s portrayed as more of a lonely, neglected wife than an unhappy woman in an unhappy marriage.
The world building is lacking, so far.
It is pretty true to the book but it is only the first episode.
EDIT: Finished episode 3, where the story diverges from the book considerably. Have to wait till next week for the rest of them.