Hotel Casa 400 is a perfect hotel if you are traveling for business. Large meeting rooms, friendly staff, coffee and tea machines available. It is also located near RAI exhibition center (around 20 min walking distance). The rooms are nice, with a large desk where you can easily work, and the beds are very comfortable. There is also free wifi available.
Furthemore, Hotel Casa 400 is not a bad choice even if you are traveling for tourism. Near the hotel, there are not a lot of things to do but the hotel is located near Amstel station (5 min walking distance), and you can reach city center quickly. You can even rent a bicycle from the hotel and bike your way to the main sites. Being away from the center, the hotel is also pretty quiet.
Concerning food, the breakfast was above average, the pub guy was very helpful and the restaurant served some tasty dishes (although we had some issues with the service and food delays).
Overall, we will definitely go back to Hotel Casa 400 some day in the future.