Location - and nothing else
We have stayed at Hotel Pennsylvania several times over the past 3 years, and each time was for one night only, bfeore boarding a cruise or after taking one. Having to catch a train home early in the morning was the prime reason for staying here.
It is close to everthing: Macy's, Madison Square Gardens, Empre State Building, and Penn Station, to name a few. At US$108 per night at the time, it was aa good deal. But that is not a good enough reason to stay here. 
This hotel is old, having been built in 1919, and was probably a great hotel in its prime. But all the glitter has faded. The lobby and the elevator are about the ony thing that are worth raving about. The rooms are small and many are overcrowded with furniture that has seen better days. We actualli thougth one of the rooms we had was a storage closet. We've seen broken chairs, tables that are falling apart, dressers whose drawers don't open, lamps that don't work and a mini-bar fridge that didn't work. But one can overlook this for a one-night's stay.
The positives about are stays were that there were no roaches or bedbugs or any other vermin, and the beds were comfortable and clean. The showers were decent enough, even though the bathrooms could have used major cleaning and re-modelling. Being on upper floors, we didn't hear much of the street noise below us. The corridors were surprisingly quiet.
The corridors are wide and long, with dark carpeting and poor lighting, so the overall effect is one of darkness. We had what seemed to be endless walks to our rooms. When we finally arrived at the room door, we found it either badly scratched or the paint peeling off. Some of the rooms had freshly painted walls, but only enough to cover the plaster patchwork that had been done. 
The front desk staff were rude, unfriendly, sarcastic, most unprofessional, and less than helpful, and this even when they had my credit card, my passsport and my printou tof our reservation confirmation. Check-in is at the 3 pm, and they will not check to see if any rooms are free before that time. And if you tell them you requested early check-in, they laugh in your face and tell you the hotel does not have an early check-in policy. The housekeepers and maintenance people who came to our room to try to fix some of the issues named above were friendly, courteous, polite and efficient, a shocking contrast to their counterparts at reception.
I've heard it is slated for demolition, but was back in 2009. It would be a shame because it is a beautiful building from the outside. I've also heard that they are doing renovations, but I've yet to notice any.
It is extremely unlikely that we will stay here again,unless nothing else is available or if it is very competitively price to other properties. Anyway, we've found better hotels in better locations with superiorly friendly and helpful front desk staff. at comparable or cheaper costs.
And do shop around before choosing this hotel.