I think red cabbage has a touch more "green" flavor so you might say green/white cabbage is milder or more bland. Of course there are white ones that have quite a kick/bite as well as those that are surprisingly sweet. I haven't grown them myself (starting seedlings of cabbage called Caraflex this year though
) so these are supermarket cabbage, though I usually buy organic.
One obvious difference that I didn't appreciate was that red cabbage stains -- the cutting board, your fingers, your salad, AND your cooked food! I made the mistake of using red cabbage when I didn't have green for a skillet dish and the whole thing turned GREY in the iron skillet
(I think there was something acidic in it like tomatoes).