My wife and I stayed at Domi and Chris's apartment for 7 nights and it was a wonderful stay :)
When we reached London, Chris met up with us nearby the apartment to give a brief introduction on the area and highlighted what we need to look out for as a tourist in London.
The apartment was located on the third/fourth floor. But the stairs was not an issue to us, except the bit on carrying the luggage up/down the stairs at the start/end of the trip could be slightly tiring.
The apartment was located at a super happening nightlife area and most sights/food places are within walking distance. Due to close proximity to some pubs, there can be some noise on certain nights (we observed that this was the case on Wed, Fri and Sat).
Nonetheless, that did not bother us at all as the activities in the day managed to tire us sufficiently to sleep through the night without disturbance.
Although it is a shared bathroom, Domi and Chris always respected our presence and always kept the bathroom vacant as often as possible.
Both Chris and Domi were hospitable and friendly. They frequently checked in with us on where we have toured in London/let them know if we have any questions.
All in all we were very pleased with the stay and would recommend anyone to stay with Domi and Chris!