I stayed in Olivier's studio for roughly 10 weeks during an internship in Paris. The studio is small, but adequate, with a kitchen and private bathroom. The cooking area and utensils were acceptable, and I was able to cook for myself for most of my stay (I left behind a knife and chopping board, so maybe they will be even better for the next guest :) ) The space is mostly clean, and as long as you vacuum often and wipe surfaces down, you should be good to go.
The location was great - you're close to Gare St. Lazare, which is a major train station with tons of metro lines going through (3, 9, 12, 13, 14), and the RER A/E are also within a 10 min walk. There is a Franprix very close to the apartment, and tons of restaurants in the area. You're also very close to a lot of fun Parisian attractions, like the Batignolles saturday market, several museums, the opera house, the Galeries Lafayette, and the Pigalle/SoPi area, which has plenty of cool restaurants and things to do.
Some things to note: the studio is on the fifth floor, so if you can't walk up and down stairs regularly this might not work for you. Also, I had some issues with the WiFi and plumbing during my stay, so just check with Olivier if you absolutely need internet/aren't ok with minor leaks. However, any issues I had were promptly addressed by Olivier, so I wouldn't worry much - just let him know and he can fix it.
I would recommend the studio if you are a student looking for a mid-term apartment - definitely a decent value for the money!