i guess the "theory" is that optical requires changing from electrical to light and then back to electrical, whereas coaxial stays the same...

i use both, mainly because my old digital cable box only had digital coaxial. my new cable box has both connections (dvd player too for that matter) and i have checked them both vs each other and they are the same.

a drawback to optical is that the connectors sometimes dont fit snugly into the component.

i have read the crap about the differences as well, but for home theater use it makes no difference. if you were planning on running your digital signal from the attic to the basement, then id use optical though...