We had a wonderful 3 night stay. The view of the castle is amazing. The flat was perfect for the four of us and there was plenty of room. The location is outstanding. You are in the heart of downtown and can walk anywhere. The metro stations are extremely which also made getting around a breeze. The flat was clean and having a clothes washer was extremely nice. If we visited again, we would happily stay here.
The one thing I would note is that since you are in the heart of downtown and across from a square, the area is noisy. Car traffic, people walking/hanging out, a bus stop right below and there fire station a block away. If you are a light sleeper, you might find it challenging.