I stayed at Martin's apartment overlooking Canal St Martin for two weeks in June 2017. The apartment was exactly as pictured, clean, and well-appointed. Martin's friend Dominique was there to meet me and get me acquainted with the apartment, and he and Martin were both available to answer any questions that came up. The temperatures were quite high for a few days, and Martin made sure I knew where to find fans to use. The bottle of wine he left for me was much appreciated, as was the soda stream to make sparkling water.
The location is fantastic! A lovely view and neighborhood, and easy access to multiple Metro stops/lines. Note that the Canal is popular at night: Martin provides ear plugs, and it was not a problem for me, but if you're a very light sleeper, it may not be the best fit for you.
Overall, I highly recommend Martin's place, and hope to return myself!