Don't make your mind with the color of the building. The hotel is much better than it appears from outside.
1- Staff is excellent. They speak quite ok English and are very friendly. Don't expect the formal service of 5 stars hotel (It's a 3 stars hotel anyway), but you can have a friendly service.
2- Room is quite large. Prefer the lake view room. It's 7 Euros more expensive but it worth it. You have a balcony/terrasse with a long chair and a nice view on the lake. It's even a bit bigger than the standard room that have a view to the parking lot. The room has two separate beds that are comfortable enough, a sofa corner, a mini bar. The bathroom is a bit small but has all you need (shower only). The TV has only German channels... but internet is free with a LAN cable you can borrow from the hotel.
3- Restaurant is good. Not fond of German food but this restaurant is good compared to other restaurants I tried in the country. Once again, the service in the restaurant is excellent. The breakfast is so so. You can have different kind of bred, ham, cheese... Nothing fancy but efficient breakfast.
Overall, the hotel is very good for the price, and the staff is increadibly friendly. One of the best hotel for the price!