I was pleasantly surprised by how much I enjoyed my stay at Hotel de Koopermoolen. The staff are very friendly. The area is right near the red light district, which is a busy and noisy part of downtown Amsterdam, but we had zero noise in our room. You have to leave your room key with the front staff whenever you leave, but it's not a problem because it is staffed 24/7.
The breakfast was also decent. The man who cooks the eggs knows what he is doing.
It's about a 5m walk from Centraal station, so it's easy to get around anywhere in the Netherlands.
Would definitely stay again.