I was in town for a week and needed a place to crash after full days of classes, workshops, rehearsals and shows. It was really helpful to have my own key, because I had to be out the door by 7 each morning and often didn't get home until 1:30-2AM. The subways were kind of a mess this summer, but getting to tines square every morning only require me to walk two blocks, jump on the G, transfer to the E, then ride that all the way to my destination.
If you're used to luxury accommodations, you might be a little out of your element at first. At the end of the day, though, it's great to be able to spend a week in NY and not break the bank on a hotel.