We enjoyed our stay at Samantha's place. It is a nice and clean apartment and the check in was not really a hassle although she was not there to meet us personally. Although it's a bit of a ride from Rotterdam center, but the location is good to reach by subway or bus and it's a bit of a walk (7-10 min) to the closest subway station. One thing that's worth to consider if you're traveling on Sunday was the bus and subway starts running at 8 AM (!!) from the closest station, since we didn't know that and we needed to leave at 6:30 AM and was surprised there was no public transportation. With another 7 min walk you'll reach a bigger station where it serves regional train.
All in all I'd stay at her place again if I visit Rotterdam.