CJ's place and my stay there was great with zero issues.
The studio is a 15 minute walk from Centraal station, very easy to find and minutes away from shops and restaurants.
The studio itself had ample space for myself and would easily accommodate a couple and perhaps even a single parent or couple with a baby or young child.
There really wasn't anything wrong with the studio so I can only recommended it as a great place stay if you find yourself in Rotterdam.