German is such a stiff language to start with, and at least to me finding the right terms in German has proven to be a challenge. It would not occur to me to use the 'polite', formal form. I use the intimate 'du' -- everything else would make me feel like I were stuck in an rpg played by terrible roleplayers only It just has this ancient and slightly ridiculous touch to me...if I'm using the formal forms it's mostly in a sarcastic, exaggerated manner. Anyway, I guess it's a matter of preference, just like everything else