A tremendous disappointment
If the mark of a great hotel is how well they meet or exceed your expectations then the Helmsly Park Lane has a lot of work to do to get to average.
Sure the location is ritzy and the rooms are large but the basics are missing.
When I book and pay for three non-refundable non-smoking king rooms with park views I strangely expect that when I check in that is what I will be given! I don't expect to be given 2 rooms on a smoking floor with the accompanying stale cigarette smells and then be told that I should have rung two days beforehand to ensure I got what I had booked! The hide.
From observations made in the lengthy waits at reception this is not an isolated issue. The hotel has poor reservation systems and the staff appear unable to cope. Most people booking in had issues with the rooms allocated from what I saw.
The issues ruined the planned experience of park views for my parents first and probably last visit to new York and there was little attempt to rectify the issue. Apologies are cheap!
I'd never stay again and would be loathe to recommend it. 
In contrast the Hampton Inn empire state gave better value.
Shame Helmsley park lane, shame.