The apartment is a great size and very comfortable. We were a group of 3 girlfriends, but still would have worked perfectly for couples. The location is terrific - a metro station with 3 lines just around the corner, 15-20 min walk to the Seine, Bo & Mie bakery downstairs (love this place!), and plenty of restaurants/bars nearby.
Checking in is a bit tricky, but the video they provide is very helpful. Ran into a challenge not receiving final deposit info and check-in instructions until the morning my flight left, so that was cutting it a bit close for comfort, but worked out fine in the end.