Hotel Hayden is a very basic but great hotel experience. The rooms are small but that seems to be a standard in New York. The king-sized bed was very comfortable. There is cable tv and waters provided every day which was really appreciated. The room also has a full sized mirror in the closet, a safe and minibar. As others have said they do have the key-pass that is required for when you use the elevator so it feels very safe. They allowed us to drop off our bags early so we weren't walking around NYC with luggage and we actually got an early check in about 2 hours earlier.
Some things to consider:
There was always construction going on during the day (again welcome to NYC) but it was surprisingly not an issue as we were out and about and it ended around 4 PM. When we first arrived there was a buzzing noise for a good 30 min coming from what seemed like a saw but once it went away the noise wasn't an issue.
The roof top bar is not opened every night. I believe it is weather permitting but it was not open until our last night there so we never got to experience it.
The shower is a rain shower which was fine but there is no shower curtain just a glass wall covering half of the shower which made it a bit messy with water spilling out in front of the toilet. Just an odd design but wasn't a huge issue for us.
The lady who checked us in wasn't very nice. Not sure if this is also just the vibe in New York but in a hospitality sense I wish that she was a bit more friendly (smiling and welcoming etc.) This is just what I've come to expect in the hospitality industry. It is also important to note that they do not monitor the Airbnb messages so do not try to contact your host via the airbnb website.