Usa Stay was a great and responsive host. I would recommend communicating through the airbnb app if you need anything or have questions. I was amazed by their response times. Stayed over a month with them for an extended business trip. As someone with some experience staying in hotels and airbnb for long terms trips to New York, I would highly recommend going with Usa Stay as opposed to individual airbnb property 'owners', since they can be super shady in the Manhattan area and you could find yourself stuck in a really bad situation. I'm moving onto another unit at a different property because they make it easy to get the keys, instructions are clear, I can trust them, etc.
This is out of Usa Stay's control, but immediate area of Kips Bay can be a little rough. If you aren't used to a tougher neighborhood you might not enjoy the immediate area. Once you get to Park and Lex, there's great restaurants etc, but the unit itself is right in the middle of some pretty real moments. The building feels safe and is nice, but I wouldn't recommend hanging outside the building after dark if you're skittish.
However, sometimes felt like old SF mission/tenderloin areas, so if that's your thing you might like it. Pretty young crowd hanging around - close to bars/restaurants like Cannibal, the 6 station. I would stay there again. It was really comfortable and started to feel homey.