True Q, so true.
I found that most Germans south of Frankfurt did not get too excited about formal/informal blunders, they were just happy when an american tried to speak their language. HOWEVER, most germans NORTH of Frankfurt are very picky about usage. Thats why I spent most of 14 years in southern Germany, Bavaria!
PS - Girls are prettier in the south. The closer you get to the Alps, the prettier they get!
Lets have an FGF Fest in Munich!