These are mostly available free online on the various mairie websites (or at least the BMD records are), but not searchable by name, so having them on Ancestry should make it easier to find what you're looking for. They had already done the Paris BMD's, but here are some new ones:
Aisne, 1792-1905
Ardennes 1791-1892
Haut Rhin 1793-1892
and also Aisne censuses:
https://www.ancestry.co.uk/search/collections/61965/