Stayed 5 nights in June. The apartment made our first Paris visit absolutely wonderful.
Pierre was very responsive from the very beginning of my inquiry. Although he wasn't able to make it to our check in because of emergency, he gave us ample heads up and his friend was there greeting us when we arrived and showed us around the apartment.
The place is perfect for a couple with a real bed in a separate bedroom. As mentioned in all prior posts, location doesn't get any better for both touristy and local experience. Louvre, Notre Dame, Centre Pompidou are all within 15 min walk and the rest, Eiffel Tower, Montmartre, Latin quarter, and saint Germain, etc. are all biking distance. We rented Velib bikes (equivalent of citibike in nyc) and didn't use the metro although the station is only a couple blocks away.
As to the local experience, Montorgueil offers more restaurants, bakeries and markets you can go around. Since the apartment has a fully equipped kitchen, we tasted some fresh seafood bought from the markets. There are also several laundromats nearby so we were able to take care of laundry before heading south.
Would definitely come back and recommend Pierre's apartment to anyone visiting Paris.