I stayed in Kim's apartment for around a month and I couldn't have asked for a better apartment or host!
Location: right in the middle of the Witte de With district (restaurants and bars) and only a few minutes walk to the Lijnbaan pedestrianised shopping streets. It is close to two metro stations and a tram stop, so it is easy to get anywhere in Rotterdam. It was also a 10 minute walk to the Erasmus MC where I was doing some work, so it was extremely convenient. There is a small supermarket on the corner of the street, but you can get more supplies in a larger supermarket on the Lijnbaan.
Apartment: exactly as advertised. Very spacious and homely, and it was fantastic that the apartment had kitchen and laundry facilities. It is on the second floor of the building, and there is a nice balcony for sitting on warm afternoons. Because I was working in Rotterdam, the study desk was a godsend - especially with wifi included. There were plenty of towels and toilet paper and other cleaning equipment. The bed was very comfy and there was wall heating in the main rooms. After arriving after a long flight, it was lovely that Kim had left some cold drinks in the fridge and some snacks! There is also a wonderful supply of cooking equipment and also spices and sauces for basic ingredients.
Host: Kim was fantastic and easily contactable. I had some issues with the washing machine and kitchen lights that were easily rectified with a few quick emails and some investigation!
If I were to return to Rotterdam, I would definitely stay here again!