We stayed in Serge's place as it has great proximity to GVA airport. Serge is a great host and was very accommodating and was really responsive. The flat is near some supermarkets and we were thankful to use Serge's kitchen to cook dinner.
One thing to note is that smokers are allowed as guests in the room, and while this may be generally ok, it was very clear that the person staying the previous night smoked heavily and this made our rest quite uncomfortable.