Great location and Betty was super quick and easy to communicate with. The flat is rather small and there's no A/C. Normally that wouldn't be an issue, since it's on the 6th floor and gets a nice cross breeze, but we happened to be in Paris during an unseasonably super hot (high 90s F) week. We were also very happy to have an elevator in the building!
There isn't much kitchen space or equipment either. Totally fine for a short stay - we made tea/ coffee and had fruit and yogurt for breakfast but if you are planning to stay for a while and prepare meals, you'll need to get creative with the space!
The flat is in a good location in Montmartre. Lots of bakeries, stores, cafes and restaurants within a few minutes' walk.