I bought 2 of these online last year late spring/early summer for the listed price (They are Out of stock), they were basically unissued. I'm sure they just sat on a shelf in a police equipment room. I checked all the gaskets and wax rings and did a positive and negative air pressure check with a 40mm filter and they performed as well as my issued gas mask at work.
3M Scott M95I prefer the side mount filter vs. the center mount.
Cheap gas masks have become scarce with all the rioting last summer in particular, almost every single person at the Federal courthouse in Portland at night when shit got dicey had a gas mask on.
If the French ones look solid and have good reviews I'd go for it as long as they take a common filter size, I didn't look but being that they're French they're probably a 40mm NATO thread pattern. I do like that it is one large lens instead of a goggle type like my personal one, I use the large lens type at work they definitely give you a better FOV.