My wife and I stayed for 5 weeks in Elisa's place while working in the city. You probably already have figured out that the location is fabulous & close to every subway line; enough said.
Pros: Wonderfully quiet and peaceful (as advertized) since faces into a back yard area (with trees!) between 16th and 17th St, so no street noise, and no-one is above you. Zero noise from neighbors. Occasional clang of girder from some distant construction site after 8am. Large living room, plenty of diffuse daylight from the skylight, comfy sofa, arty decor, good books. Indoor temperature was 70-80 F (nice to come in to during winter), controlled by opening window. The place is well-organized, tidy, enough kitchen equipment, and labels on things. Elisa, and her friend who met us to let us in, were both very responsive to questions by email.
Cons: Bedroom separated from living room only by hanging bamboo screen , not actual door, so little privacy. Mattress a bit saggy (may not matter to you); some applicances a bit worse for wear (land line phone didn't work correctly, no printer ink - Elisa offered to reimburse if we replaced these but we were too busy). North-facing windows, so no direct sunlight. The only food preparation area is a free-standing island which also serves as the dining table.
So you can see the cons were minor - on the whole an excellent place to stay.