short version: liked it and if you liked other grishaverse books youll like this one (though i know liking crows doesnt mean you liked s&b and other way around, but still. I would say this is like a mix of the two, but like, if your favorite things about the other series are specific characters then you wont find most of the crows hanging out being iconic)
long version: its in a difficult position of having characters we already know, but a lot of things about them are different. So storylines like Nina's relationships with the people around her may be a bit weird at first, but they definetely all grew on me and I love the direction her story takes at the end.  same goes for what Nikolei gets himself into. Overall, I enjoyed the last third of the book the best and really liked what they did with most characters though I'd like to see a few of them more in action in the second one.
when it comes to her writing, ive always had mixed feelings, but i think i can identify them now, I think her best moments are when she switches to first person pronouns, i just feel it fits better with her style and it makes it easier for me to connect with the characters. The way she does povs normally wasnt exactly my cup of tea though im still not sure why, but its okay. there were moemnts that i was very very moved and got all emotional and excited and moments when i know didnt reach their full potential with me. I like the magic I like the ending yes a lot. I like how we got a deeper view into

Zoya's

past experiences and how it addressed things about

the darkling

and I feel that that really completed the image of what happened in previous books. 

the mourder suicide felt almost iconic though im not sure whether that is slightly ruined by the fact that she didnt actually die or not

cant believe the you and i are going to change the world line is someting he said to zoya such a shame so many people wont know that its one of his iconic lines and think its just a darklina thing (not an attack on darklina i just like knowing that its bigger than that because thats what i expected it to be from thebeginning)