I liked Come Tumbling Down okay, but I feel it repeated previous plots a bit. The worldbuilding and writing was still good, but I felt that character growth was taking place mostly between books. Both the boys involved were pretty useless for most of the time, which is especially unfortunate with the trans guy cast in a (learned?) helplessness and inability to be of help.
I also felt that despite the good writing, several passages were made to be quippy and quotable at the cost of fitting in well with the book, which was jarring.
Honestly, despite the book setting up future books, I feel the series may be best served by ending at this point, before repeating the same plot (there was not much plot to speak of) and sensitive characterisations becomes too tedious. I don’t think I’ll read more in the series and instead try other books by Seanan McGuire.