I just finished it a while ago.
My comment will have lots of spoilers, obviously.
I loved it, which absolutely surprised me. I thought it was going to be a boring, sad book and i was nothing. I mean, yes, it was a book about grief and recovery, and Harry (and later Thomas) are sad the whole time. But the book itself is not sad, it is funny sometimes, it is interesting, the pain feels true and there is a lot of hope. So yes, I loved it.
I think 4.5/5 is fair. There are a few things that bothered me. The sudden level of Fitz (who I love!) sounds to much to "somehow, Palpatine is back". Lara not knowing what a soulgaze is, even when Harry saw Ramirez soulgazing her. I can imagine excuses for that that could work in universe, but still feels clumsy. And overall, the True Love protection thing.
Of course, there are also a few thing I did not like personally but that do not the book less good. For example, I really wanted Harry to destroy Thomas hunger. And the hunger in his baby too.
I also did not like that Lara did not realize that she was becoming addict to Harry until it was too late. I realized it as soon as Lara mentioned that she had not needed to feed in the whole week. A moment of thought and I suspected Mab knew it too. I understand Harry did not realize it, because he is not in his best mental state and he was so dead set in saving Thomas that he became blind to other things. I fully understand and accept that. But Lara experimented it, she is clever, she had been surrounded by addicts her whole life. She should have noticed it. The only in universe excuse I can think is that she was in denial, but in that case a line like "I should have realized, I did not want to see" or something like that would have been perfect.
The most surprising thing, is that we did not have any resolution to the things BG seemed to promise. We still don't know anything about what being a Starborn means, and Harry not even mentioned that his time to speak with LTW approaching. And we did not have any resolution about the wedding either. But when I say that this is surprising, it is especially because I do not care. The book let me satisfied without addressing those things.
I won't comment here the things I liked because there are too many, but I will mention two topics I have questions about.
1) What exactly involves the arrangement with Etri. Can Harry and Maggie visit Thomas' son? Could Lara see him from time to time? Can Molly check on him and report to Thomas?
2) where was Marcone, what was he doing the whole year? I mean, I understand Jim did not want to include Marcone because the book is already crowded, but it is weird that Harry had not mention anything, not even asking Gard about him. Harry mentions a lot of people helping in the reconstruction of Chicago and i found super weird that there was not even a passing line to the Baron.