We were a group of 4 friends (in our 40s) and found Béatrices apartment the perfect place to stay for our 3 day weekend visit. The apartment itself is very spacious with a sociable set up. The large windows and 6th floor views are fantastic; accessible via an authentic elevator. Béatrice left essentials in the fridge and allowed use of tea, coffee, condiments etc which was very generous. The location is fantastic - only a 8-10 minute walk to the Abbesses metro station (which gave us access to all the major sites within a few stops). This area itself is a prefect with many fantastic shops, bakeries, cafes, restaurants (fab for sitting outside in the evening!) We were lucky to be visiting when there was a harvest festival in Montmartre and we enjoyed local wines and cheeses whilst sitting on the steps outside the Sacre Coeur. I honestly would recommend this as the best area to stay in Paris.
We found Béatrice to be a friendly and informative host - she gave us many useful tips and pointed us to the best areas, and also very kindly organised our return airport taxi (only 20 mins to CDG) I recommend both Béatrice and her apartment very highly and would be delighted to return again :-)