Marvin's place was very well located for us. From this location, the Eiffel tower was just around a 20-minute walk away and we were able to walk all the way to the Luxembourg gardens and even the Notre Dame area. We were traveling with our 2-year old and brought the stroller, so we wanted to avoid the not stroller-friendly metro - if you are bringing a stroller to Paris, make sure it is light and narrow. We saw people literally throwing their strollers over the turnstiles at the entrance of some metro stations.
The place was also very quiet and private, exactly what we wanted to get proper rest after walking around all day. The apartment is located in the central area/patio of a building with tall windows facing the patio area - though little to no foot traffic in this area.
When travelling with our son, we seek to bring as little luggage as possible so we always look for places that have an in-apartment washer. Marvin's place had a washer but we were surprised by how violently the washing machine would shake when it entered the spin cycle. We were not able to use the washer much but luckily, was not needed at the end. If the washer is important for you, make sure to check it as soon as possible so you can communicate any issues to Marvin.