Shout-out to staffer, Alexander
The very best thing about this hotel was the front desk staff person, Alexander. We first met him when we checked in after midnight, as our flight was delayed. Despite the late hour, there was a line-up and Alexander was the only person working the desk. He took extra pains to take good care of us even before being told that we were event planners (although not there to plan an event at the W). Upon being told we were there to celebrate a special occasion, he upgraded us to a higher level/bigger room although we would have to move the next day as it wasn't available that night.
The move was a very good thing. Not sure if the room we got the first night was the level we'd booked (maybe a Spectacular? certainly not the lowest level), but it was pretty teeny. Not as small as the one that another reviewer described as a prison cell, but certainly smaller than we expected for $400/night, even in NYC. We were on the 3rd floor with a view of the parking garage. The air conditioning was atrociously loud - and intermittent - so it was very difficult to sleep especially since it was pretty much right next to our heads. 
The next room we had was much better and of a decent size (read: small hotel room in any other city). The furnishings and finishing were fine and we looked out on Lexington - which is LOUD at night. Although the sound of the sirens was somewhat masked by the aircon unit.
Wifi at $16.95 was exorbitant so we forewent it in favor of the free wifi in the lobby. Our iPad seemed to work well enough with the free wifi but my laptop could never get a good connection. The breakfast service in the restaurant was generally pleasant and the food was acceptable but the coffee was dreadful. I discovered there's free coffee on a small table near the Concierge desk on our last morning - not sure if it's there every morning but it was a godsend at 4:45 am and it was much better than the restaurant brew.
Bottom line - we had a very nice stay because of Alexander and the location is very good if you want to be uptown. I don't know if we'll stay here again next time though unless the rate is much cheaper.