I didn't get the chance to meet Elena in person, but she provides a very detailed direction on how to get to her place from CDG airport. We spent 3 nights at her place and i would say the location is Great, Awesome and super duper convenience! the neighborhood is safe and peaceful, It takes only 7 minutes walk to the nearest metro station.
If u enjoy a morning run, from Elena place to Champ de mars is only 5minutes and i had the best view/moments running under the eiffel tower! Simply Awesome!
The space apartment is sufficient for 4 adults. The only problem we face is the water pressure and temperature for the shower, still acceptable though.
Overall this is a great place to stay!