As far as the review goes, I'm always disappointed at how many of these pieces struggle to get past the cliche of Flaubert as shut-in, ignoring his North African sexfest and only skating over his endlessly dazzling intellectual chatter.
For anyone able to read French, Rouen University has a magnificent repository of the letters, many with scans. https://flaubert.univ-rouen.fr/correspondance/correspondance...