This is a lovely place to stay in a great location!
We've been to Paris a couple of times in different areas both in more stylish and more basic apartments. Josephine's place turned out to be the best one we stayed in so far: it's modern enough and also cozy enough, you can feel at home. And also: it is in a great location with lots and lots of restaurants, bars, cafes etc. nearby. Also it is right above a shop where you can stock up on everything you need for your stay - very very convenient.
On this trip we were 3 (a couple and a friend) and the apartment is just the right size (two couples would work as well).
Contact with Josephine was fast and very friendly - it is a pity we did not meet in person! Check in is via the concierge of the house - utterly uncomplicated.

The one thing we won't miss are the stairs: the apartment is on the 4th floor which means 8 stairs up. The stairs are old, steep and well used (uneven, bent wood). If you have trouble with stairs... this would be the one and only deterrent. Otherwise heartily recommended - we'd love to stay here again.