Matthieu's apartment is located on a quiet street in a fantastic location in the 7th. It's just off Rue St. Dominique, which boasts lots of retail stores, pastry shops and bakeries, grocery stores, and restaurants. We were very close to the metro and bus lines (although the metro wasn't usable, as we were here during the transportation strike), but the bus lines are also very efficient, getting us to further places, as needed. We ended up walking around to nearly all of the places on our wish list, simply because the weather was cooperative and the location was ideal for us. We loved walking to the end of the block and picking up breakfast from our chosen, favorite bakery and walking to our destination of choice. From the end of the block, you get a spectacular view of the Eiffel Tower.
The apartment itself is plenty big for two people, and you could definitely do a family of four (kids) or a close group of 3 adults, since I believe the couch is a convertible. The toilet is a separate room, so someone getting ready can still access the bathroom, and the kitchen was well-appointed, and we cooked dinner for ourselves a few nights after lots of walking/museum-hopping. The Wifi was lightning fast-- a pleasant surprise-- which was helpful for night-before planning and even watching some shows on Netflix to unwind after a long day. Also, the bay of windows was lovely to open up via the automatic blind switches to bring in some natural light. Located on the 2nd floor, it was easy to get in/out, and the small elevator was quite helpful with luggage.
I would definitely recommend this place to family/friends :)