We've taken several family vacations to NYC and this was our favorite location to-date.
Ten of us (six adults and four teenagers) had plenty of space. The ground level includes two bedrooms and bathrooms plus the kitchen/dining room. The other two bedrooms and third bath are on the lower level with the living room and laundry. At first it seemed odd to have the two common spaces on separate floors, but it worked out nicely for our group.
The neighborhood is quiet, with a short walk to the subway (local and express trains), Central Park, Hudson River Greenway Trail, and groceries (we frequented Trader Joe's and Zabars). The kids felt comfortable venturing out on their own, enjoying the local bakeries and shopping.
We hope to return!