Let's start with the (many) good things. The location is perfect and cannot be overrated. We enjoyed both hanging out in the chic and vibrant Montorgueil quarter, and reaching easily all central parts of Paris. The place was spacious and clean, despite some signs of wear in the bathroom. photos are accurate in this regard, with the one exception of upstairs gallery which is difficult to stand in if you're taller than 1.60 m. Also it was strangely noisy at night, possibly because of air conditioners located on the roof.
Two things made our stay a little less perfect than it could have been. First, the elevator did not work when we arrived, and in the next days it only partially and unpredictably worked. While clearly it wasn't our host's fault, nor could she fix it on her own, it would have been nice to have her contacting us to check if it was fixed. it is also important to note that even when the elevator is working, there are still 30 stairs to step up before reaching it, which may be a major obstacle if you're disabled.
Second, we had troubles reaching our host in the couple of days preceding our arrival (when it is most urgent to coordinate check-in arrangement etc.). We called upon landing, as was agreed beforehand, but still waited over an hour with our luggage outside the apartment. it should be mentioned that the agreed time was indeed an hour before the official check-in time, but still it was disappointing to wait for the host to no avail. On the other hand, the host was very generous in letting us stay a couple of hours after the official check-out time.
All in all, the listing is highly recommended, if better attention is given to communicating with the guests before and during stay.