A total of 6 of us (2 adults, 3 teenagers and a toddler) spent a week at 18 Riverside and had a wonderful time.
The cottage was well equipped, clean and in a fantastic location. I spent many happy breakfasts sat on the balcony looking out directly over the river.
The cottage is set in a peaceful location but also offers great access to the town (the teenagers walked in a few times within 15-20 mins) and lots of other attractions.
Our only criticism, if you could call it that, was a lack of internet access and limited TV channel choice. Having said that, we were very fortunate with the weather so spent a lot of time outside anyway. If the weather hadn't been so good this may have caused some boredom to the teenagers!
Overall though, if you are looking for a great base for your holiday in Whitby you can't go far wrong with this.