Loved this hotel, the bed was comfy, the bath was long enough for me(!!), and the location is perfect! We stayed on the 11th floor and could barely hear any of the street noise from the surrounding areas. Everything was nice and clean, and easy to use.
We did have to pay a €100 deposit upon arrival which I was told would be refunded upon checkout, however I haven't received it yet (3 days later).
We pre-booked late checkout but ended up leaving before the original checkout time anyway and didn't get charged any extras, so I would recommend looking into that (after you've booked) as a safety net!
Definitely will be booking again next time we visit Rotterdam!