I stayed at Viona's place for a conference I had.
The appartment is 10 min's from the airport (or Palexpo)/and the city center with stations just infront of the place. It is a lovely appartment in a pleasant building, quiet and clean. The flat is nicely equipped with TV, WiFi, kitchen, refrigerator etc. Viona was kind and easy to communicate with.
The main drawback in my opinion is that the price is high, but you should know that almost everything is expensive in Geneva, so depending on your needs you should compare the prices with hotels (which was irrelevant for me in this trip) and then decide.