We (family with 3 kids aged between 8 and 15) stayed at Christian's apartment for 5 nights. The location of the apartment is great - in walking distance to several cafes, restaurants and shops, as well as to public transport and the Thames/Westminster abbey. Next to the building is a small park with a playground, which might be practical for families with smaller kinds. Despite being in the middle of the city, it is very quiet, especially during the night. We did not hear any noise from the neighbors.
In the afternoon until 10 pm, there were people using the sports area next to the building, especially for playing football. Our youngest went to bed before they stopped playing and was a little disturbed by the noise. With the window fully shut, it was ok for her.
The apartment offers 4 bedrooms (2 double, 2 single) situated on two floors. The entrance is on the second floor, there is no elevator. The beds are of good quality and very comfortable. The bathroom and the extra toilet are small, but functional. The apartment is not huge, but provided sufficient space for the five of us.
All "essentials" you might need during your stay (e.g. soap, shower gel, washing detergent, dish towels) are provided, which is very convenient.
We had several questions to Christian during our stay, he always answered within a very short time frame and was very helpful. It was also possible to deposit the suitcases in the apartment prior to the official check in and after the official check out time, something we appreciated a lot.
We did not cook any meals and only had one (take away) meal in the apartment, so we cannot say much about the kitchen. The table is rather small, but ok for a group of five.
Unexpectedly we needed to wash some cloths and were glad of the washing machine and that detergent and laundry rack were available.
Overall a very good choice for staying in London for a few days. Thanks Christian.