Short version: I can confidently say that this is by far the best place to stay in Manhattan for a couple or family. The place is gorgeous, very spacious, and in a wonderful location. It is well appointed with good attention to detail geared toward comfort.
Longer version: My wife and I, my mother, and my one year old son stayed here over Christmas. The place is in a great location, within walking distance to alphabet city, soho, lower east side, east village (so good restaurants as well as shopping.)
Small quiet elevator building on a quiet (by NYC standards) street. The elevator works well, is spacious, and goes right up to the unit. There is a large foyer that feeds into a beautiful, very large (actually large not just large by NYC standards) light-filled living room with lots of windows. The unit is decorated tastefully and comfortably. Well equipped kitchen with sharp knives, etc. off the living room. Three bedrooms in the back, separated by a long hallway. Good separation between living area and bedrooms.
The master is a very large suite with a very comfortable tempurpedic bed, comfortable pillows, etc. Good curtains, sound-proof windows, etc. The second bedroom is decent sized for NYC with a comfortable pull out couch. The third room is a very well set up nursery with a crib, changing table, etc. The setup is great for a couple or family with kids. It would also be good for two couples and one child (but one of the couples would have significantly more space/ a better setup than the other).
The host was very responsive and helpful. Overall I really recommend this place and would book it in a heartbeat.