Stayed at Stroom for New Year's Eve, arrived earlier than check in time but after having a quick drink in the bar the friendly receptionist said our room was ready and we could check in nice and early. We had a studio room and it was absolutely spotless. Room had a double shower and large bath, a small issue with a leaking hand basin was dealt with quickly and efficiently by a lovely gentleman (May have been the manager) he was very apologetic and offered us a free drink at the bar for the inconvenience (not really an inconvenience to us and we didn't bother going to bar for a free drink)
I agree with some of the other reviews regarding the surrounding area of the hotel being rather run down but the hotel itself is good value and the staff couldn't be more lovely and will give you lots of good advice on places to go and transport etc.
I would return to Stroom again when next in Rotterdam