I stayed for two weeks while working at Columbia. The area is relatively quiet - for NYC standards - and nicely located just around the corner from the 2,3 express subway, so getting to the UWS and downtown really only takes 10-20 minutes. Columbia is within walking distance. The Harlem neighborhood is vibrant and I never felt unsafe walking the streets alone.
The apartment is charming. The permanent housemates, who are very nice, had just moved in when I arrived and were doing everything to make the place a home. The room was as pictured and had everything I needed (bed, closet, desk) while the living room was a welcoming space to hang out. The kitchen had everything I was looking for, too. Overall I had a great experience.