My experience supports the ISO 80 rating. In fact, as a long time HC-110 user, I can say that most of the films I develop with HC-110 require me to shoot at 2/3 to 1/2 of box speed for optimal shadow detail. My testing has even led me to shoot Efke PL100 at EI 32. This is based mainly on dil. H concentrations in hand inverted tanks.