If you're an average tourist who expects good 3-4 star then this is not the place for you...but if you like something different, artistic and real then you'll have a very interesting stay.
We stayed with Gerard and his son for 3 nights. Yannick wasn't there during our stay but Gerard was an attentive and generous host. He provided excellent directions on getting there and lots of local knowledge. We had very interesting conversations in French and a little bit of English. They are artists and their home reflects their eclectic tastes.
The house wasn't as clean as we like, particularly the kitchen and bathroom but we did use both with no problem. Perhaps with Yannick away, normal cleaning had been overlooked. The garden room and garden were lovely and bright and we had breakfast there each morning.
Our room in the attic was clean, and our bed and bedding were fine. The roof line did cause us to stoop a lot and we both felt the strain on our backs. The long climb down the spiral staircase in the night to go to the bathroom was a bit precarious but younger people might handle this better.
The neighbourhood was lively but if I was a single female, I'm not sure I'd feel comfortable walking to the street door due to large groups of boisterous men congregating day and night. There were plenty of cafes, brasseries, a supermarket, chemists very close by, a street market popped up one day, and we walked easily to Montmartre.
Overall we enjoyed our stay and feel we experienced part of the real Paris, not just the tourist attractions.