I really like Phillipa Georgiou, both iterations, and this book fleshes out Emperor Georgiou in her current predicament of being stranded in the Discovery verse. Witty, not in the least bit squeamish in her cruelty, but there's a redemptive quality that the "good" verse draws out no matter how hard she fights against the act.
I did not mind the plot but it was a little meh. The full focus on Georgiou smoothes most of that out, for me anyway.