There is absolutely nothing that I didn't like about this book, and probably far too many that I loved to name. Baroness Orczy's The Scarlet Pimpernel remains one of my favorite books, and although this book did not show me a different side to the Reign of Terror and I did at times wonder how much research had been done on the matter, it was nonetheless an extremely compelling and striking portrayal of the Revolution, as well as an exciting story of secrets, romance, adventure, and even a little magic.
Side bar, I didn't actually read this book--I listened to it. I'll be honest enough to admit that the only reason I knew about this audiobook was because I'd heard it was Tom Hiddleston reading, but once I saw the plot summary (French Revolution! Young lovers! Gypsy magic! Automatons!), I knew I had to read it. Maybe Hiddleston's great sense of volume, drama, and timing (not to mention his amazing accents) had a lot to do with my enthusiasm for this book (and there's something a bit more suspenseful and breathtaking when you can't see the words and can't skim the page to see what happens next, which is what I sometimes do. There was actually a moment in the book where Hiddleston's reading scared me -- the man's voice is amazing), but Sally Gardner has herself an excellent story all by itself.
(I wonder if Tom Hiddleston reads the sequel as well.)