Let's start with the good stuff. David's place was great. The location is excellent. It's close to a bunch of metro stops and there are a bunch of major tourist sights within a 30 minute or less walk. His place has everything you need and it's clean and pretty (I'd say above the norm for similarly priced AirBnB places). It has beautiful parquet flooring and crown molding and it overlooks the street and has a partial view of the Basilica Sacre-Coeur. David was communicative and thoughtful. We came the day after Christmas and he gave us a neighborhood walking tour book as a gift. He even sent us a Happy New Year's Eve message and photo from his family, which I like the rude jerk I am forgot to reply to (sorry, David!). He had a couple restaurant recommendations, which I found useful. The one that's really close to his place and one of his favorites had some of the best food I had in Paris so I recommend taking his recommendations if you need something to eat in the immediate area.
I'd say the only thing that could be improved is the pillow situation. There were only two pillows and they were a bit thin. So if you come with someone else and both like to double up on pillows and don't bring your own, you could have some trouble sleeping but we made do with our airplane pillows and clothing bunched up.
Another thing to be aware of is that there's no couch. There is one chaise longue and a bunch of wooden chairs with padded seats but if you're looking to spend a lot of time hanging out in David's place it's something to be aware of. I don't think it's a negative - just something that some people might not like. It wasn't an issue for us but we mostly just slept there and were out and about the rest of the time.
David's place was great and I think most people who choose to stay there will be happy with their choice.