The studio was great! I'm sad I didn't get to spend more time talking with JP, but he and his family, including a new baby(!), left on holiday shortly after I arrived. Everything was just as described, and I have no complaints. For reference, i was in Geneva to work at the League of Nations archives at the UN complex, and the commute was long, but no problem. I always like staying some distance from my work, in order to get to see a city, and this worked well in that regard. I could walk (1 hour 15 minutes or so) or use public transport (50 minutes or so) and never had a problem. If you're in Geneva for longer than a couple weeks, I suggest getting the TPG monthly pass, so you never have to worry about how many stops or if your sixty minutes is up should you want to stop along the way. If you use public transport frequently, 70chf is worth it.
Really though, the studio was perfect for one person, and my girlfriend was in town for a few days and it was plenty roomy. It was nice having TV for Euro 2016 as well. For what it's worth, I'm rather tall ( just about 2 meters, 6'6+) and though it was a tight squeeze in terms of the ceiling, I never had a problem. If I end up back in Geneva, I'll definitely look into this place again!
Thanks!