I spent only one night at Markus' place, but I was very satisfied with my choice - it was also an excellent value for money.
Markus was very flexible in accommodating my (early) check-in and (late) check-out requests. Communication between us was also very timely and efficient.
The apartment is located in a quite and safe residential area of Geneva (Grottes/Grand-Pre), and the bus number 8 (going to the UN) passes down the street.
The room was very clean and bright, and equipped with all the necessary furniture and storage space. The windows have shutters that close completely if you do not want sunlight to wake you up in the morning, and the acoustic insulation is optimal.
Clean towels and bed linen were provided.
The internet connection also worked very well and, importantly, there is a fully furnished kitchen that can be used.
Markus has a female dog that is very quite and calm.
Overall, I am very satisfied with my choice and I would chose Markus' apartment if I happen to be in Geneva again.