Great service and location, if a bit dated
Our stay at the Waldorf Astoria was one of the best hotel stays in a while. Service throughout all aspects of the hotel was consistently outstanding: from checkin (where someone called to followup a little while after we got to our room), to housekeeping, and the restaurants. It was truly hospitality as it should be. 
As others have indicated, the guest rooms are a bit dated and small. Fortunately, we knew that in advance and got stayed in a suite. Even so, the bathroom was the same size as the regular guest rooms and it is difficult to navigate something so small. How did our counterparts of 70 or so years ago do it? :) 
The location is great: along the hear of Fifth Ave, a couple of minutes from Rockefeller Plaza, St. Patrick's Cathedral, etc.