Me and my boyfriend had a very comfortable stay in Justine's apartment. Its is compact and bijou, this is perfect if like us you are planning on being out for most of the day, there's not a lot of space if you're wanting to sit in and eat etc. but this didn't bother us as we went ouf for most of our meals. Justine has all the amenities in terms of tea/coffee, shower gel, and towels and was a very helpful host in the run-up to our stay and with the check-out process.
The check-in process was very easy, located in Belleville it is super close to the metro which was perfect and there are bakeries and supermarkets in the area as well as some lovely food places and bars.
The biggest problem for my boyfriend and I was the space within the bathroom, something that others had mentioned in the reviews too. There isn't space between the toilet and the shower although there is a curtain that divides the two, we found that we were either using the toilet with our feet in the shower or sitting sideways. This didn't impact our experience overall but it's worth noting.
Overall, we had a lovely trip in Paris and found Justine's apartment to provide a great base for our exploration of the city!