Left to Right:
Matte, Semi-matte, Light Sheen, Gloss, Nothing
If you compare specular highlights you can see a difference between semi-matte and light sheen. Light sheen highlights are brighter and more sharply defined. Diffuse shading area is broader on the semi matte. Not dramatic, but perceptible.
FWIW, I tried to be very consistent with application and cleaning between subjects. Each tack only has a single coat.