The stay at Kaitlyn's apartment and New York in general was fantastic! Kaitlyn is a great host with lots of advice for where to eat and what to do. The apartment is clean, the room is spacious enough to unpack some luggage. For the naive European that thinks windows are not only a source of light but also isolate or ventilate the room: not the case in the US. They only ventilate. (Yay for climate change!) Ask for heating instructions when traveling in colder months.
The traveling to Manhattan was easy to do using the subway. I also recommend using the citibike system to go e.g. to Brooklyn Heights or Williamsburg or in Manhattan. The neighborhood is so-so, lots of litter on the street, but seemed relatively safe even at night for people with minimum level of "street smartness". Overall, I am very happy with my choice.