Staying at the apartman of Kees and Marjolijn was a blast.
It is what it is - don't expect anything fancy, but what you get is perfect for staying a couple of days in Rotterdam and exploring the city and the other parts of the Netherlands.
It's a 15-ish minute walk from the central station in a vibrant neighborhood (hey, you have a jazz bar in the area!), this cosy underground accommodation can be a very good "base of operations". Highly recommended.