We did not see Guillaume (picked up the keys at the concierge) but he was very reactive during our emails exchange. The flat is great and well located 1 min away from underground (even if it's not one of the main lines and you might need one or 2 changes to get where you want)! The view is amazing! However, I would say that the flat would benefit from a better maintenance (was not very clean, one window is broken, some basic furnitures were missing). All in all, I still think it's a pretty good deal!!