I stayed at Mercy's in May and it was great. Her apartment is exactly what you see on the pictures. It is located in Upper Manhattan in a safe neighbor with lots of restaurants and shops around and very close to the metro. Mercy was not in the US when I stayed there but she was extremely helpful and we were always in touch, she would answer any questions almost inmediately and left an emergency contact in case she didn't reply within 30 minutos, it was not necessary because she answered inmediately.
I would definetely stay there again.