I ate at the Oak Chalet tonight and the food was absolutely delicious! The best German food I've eaten yet. The atmosphere is cozy, subdued lighting, lots of wood and big German steins. There's a fireplace off to the side near the entrance. It was clean and comfortable.
They don't have a separate room for a RD or shower. The dining room is L-shaped, and the short part of the L (hope that makes sense), is where they would put a larger group. There was a small (under 10) anniversary dinner going on while I was there, but they were just in the main dining room.
I heard it was a very quiet place, and it was quiet, but you didn't get the sense that having an animated group would be a problem. The staff was nice, service was good. I really have no complaints at all.
The one thing that would have really put it over the top would be if the staff dressed in the traditional German clothes, like they do at some German restaurants. But that's really a minor detail.