My stay at Marie Christine's place was awesome. I would always rent this apartment.
Marie-Christine is a very nice person. She had the place cleaned and the towels & bedsheets ready upon my arrival. She even helped me carry my suitcases up the staircase.
The neighborhood is super quiet. The neighbors within the building are quiet too. There is a little garden in the building. There are 3 major metro stations nearby. The location is simply amazing, it's very central. It's in the Marais but also close to Georges Pompidou & Chatelet.
A lot of light comes into the room during the day. The apartment is on the first floor but there is another staircase to get to the room, so it's like 2 stories up. The room has everything you need, it can carry up to 3 people but I find it more ideal for 2 only. There are machines to make any type of coffee you like. There is a microwave & a fridge. You can even cook if you like, but who would really want to do that when in Paris :)
There is always warm water to shower and the room is well heated. The bathroom is new. There is no washing machine but there is a laundromat on the street.
I can't express how amazing the location is. I was able to walk all around Paris because of that. I rarely used the metro. It's 20 minutes max to St. Germain. Around 30-40 minutes to Opera.