"Love the characters"
I've listened to all of Tana French's mysteries because I love her characters so much. Her plots tend to be too implausible for my tastes, but I'm not a huge fan of the mystery genre.
"Not as good as A Discovery of Witches"
Shadow of Night didn't have as much suspense as A Discovery of Witches did. There was a lot of reveling in historical detail at the expense of moving the plot forward.