Big fan of the books, watched the whole season in one day. I think they've captured the characters really well. It was fun to watch and you didn't get bored and want to do something else. The CGI works well enough not to distract you.
It for sure has a target audience in mind, kind of like Netflix's answer to Wednesday (but imo better). A dark edgy but also a bit comical series for teens. I don't remember them talking as much about death, or the romantic tension being as noticeable in the books. They're clearly trying to capture those who feel left out, classic escapism, like Harry Potter... a selling concept.
Another difference is the lack of time. There isn't really a sense of enough time passing between scenes. The fast phased nature keeps you engaged but doesn't really let you settle in to the characters or get a sense that they've really had the time to get to know each other as well as they say. However due to the medium change it is however maybe impossible to get to know the characters on the same level. I can appreciate both versions for their strengths.