Not actually that great. Before arriving, I never would have expected that I would actually be counting down the days until I got back into the US to drink American beer, but that seems to be the case. While the price and convenience here can't be beat, I'm already getting bored of the few available styles ("Would you like a pilsner, a hefeweisen, or a dunkel?"). To be fair, my experience has mostly been limited to shops and bars, with only a few brewpubs and beer halls with a longer beer list, but damn Germany, I'm disappointed. I haven't yet had the "wow, that's damn good" experience in my time here. (I'm sure I will find some excellent beers with a little more effort, but I expected it to be much easier.) This article sums up my feelings pretty exactly.
Nine days until Chicago! I will drink ale, so much ale!