Amazing 2-month stay at Mathieu and Gissela's place. The pros are: the host is extremely nice and responsive; excellent location with 3+ metro lines within 10min walk; there's washing machine; basically anything you need.
Now the cons: as a lot of people mentioned, there can be a lot of noise when people enter the building, but the noise didn't really influence my sleeping since the bed was on the second floor. Also, there was only one proper duvet, so it was very difficult for two people to live there without buying your own duvet.
Overall I think the pros definitely outweigh the cons. I had to leave early due to coronavirus, but I'm really glad this was my home in Paris for the short time I had here.