Chelsea Inn has a unique check-in process that may seem weird at first (I was a little unsettled), but when everything is said and done, it worked okay.
The hotel sends you an online form to fill out and when that is done, it will send you the codes you need to get into the building and into your room.
The form has a few typos, but it is legitimate.
If you want a stay where you can come and go as you please without interacting with anyone, this is great.
The best part of the Chelsea Inn is the location. It is within one block of several different subway lines, so getting around was a breeze.
The only real issue I had is one that seems common in older New York City hotels- noise.
The walls are pretty good with soundproofing, but other guests are incredibly audible through the door, so light-sleepers beware.
Overall, great stay. I would do it again.