We stayed at Mat's place for a total of six nights. The place was really easy to reach from Gare d'Est. When we arrived, Mat was not home and we waited a while outside in the sun.
The room felt a little smaller than it looks on the picture and the staircase is pretty narrow and noisy when walking up and down. It was great that there was a little room with toys right beside ours. Mat offered it to our son and he had great fun playing around.
Walking up the staircase, there is another bed with no door to seperate from the walkthrough and there were two language students sleeping there. They were super friendly, but it felt a little strange to have to walk past them when they were sleeping and as they slept about 4 meter above our heads (without door) every noise could be heard and they could probably hear everything from us as well (especially our little one). Another noise that felt a little bothering came from the Metro which passes close by and makes the place vibrate. After a while we got used to it.
We were offered room in the fridge and cupboards in the kitchen and could use everything that we needed. The kitchen, living room and bathroom look really nice. A few nights, Mat was sleeping in the living room which connected to the bathroom, so we had to walk past him in the morning and tried to be most quiet.
In total, we enjoyed our stay in Paris despite the lack of privacy. The other guests were nice people and we got along pretty well.
We addressed this when we were still there and heard that Mat plans to make a few changes to the appartment which will improve the situation.