You can see the difference between Memento's Tuxedo Black ink and Versafine Black Onyx, for example. Versafine is a much richer more opaque ink that really coats the stamp giving good coverage.
Hero Arts mid tone wet cement would seem to be a gray/grey tone, it is more of a browney or taupey gray/grey if that makes sense.
So what are your go to neutral inks? Do you prefer dye inks or pigment?
Inks: Hero Arts mid tone; Versafine; Memento