Great stay at Charlie's place! The studio is small with a fold out sofa-bed, a kitchenette containing a minifridge, hotstove, microwave, and dishwasher, and a shower. There's also a television, a mirror, and a fold out desk and chair. A shared bathroom is down the hall. Charlie left a lot of thoughtful touches, like a plug adapter, hair dryer, kettle, and bowl of fruit, so it really felt like it had the amenities of a hotel -- but was more personal.
The location of the studio is fantastic. It is within walking distance of the Louvre, Notre Dame cathedral, Opera Garnier, Galleries Lafayette, etc. I walked everywhere and only used the metro once to get to the Opera Bastille. That said, the metro is great (much better than the subway in New York) and I wished I used it more instead of walking through the heat and smoke sometimes. The Cadet metro station is 2-minutes from the apartment.