Loved it, loved it, loved it
Our first experience here was arriving at the hotel at 10am to drop off baggage. Reception tried their best to find us an empty suite so we could get refreshed etc, but were unable to. However, they took our baggage and provided us with a morning tea and access to the conference facilities which were great.
When we got back to the hotel that night, our bags were in our room, on luggage stands and we had another welcome pack. It is really these little touches that set this hotel apart.
This was our splurge accommodation on a four week trip of the US, and it was totally worth it. We would happily pay to stay here again. 
Room service prices were happily reasonable and we used this on occasion. The menu was varued and the food excellent. Breakfast was included in our room rate and we had $70/night allowance for breakfast, so we could basically order what we wanted whether through room service or in the hotel restaurant. We used both during our stay. Most importantly, the bill at the end was correct.
We had to be at the airport by 5:30am on the morning of our checkout which meant leaving the hotel at 4:30am. I went down the night before to pay our account and check out. Reception asked me about breakfast and when I mentioned how early we were leaving, they arranged and booked a cab for us (which showed up on time) and also arranged breakfast to go - this is the kind of service you can expect from the Hay-Adams.
The room was great and the toiletries lovely.
The hotel is centrally located and do visit the bar - it has a history all of its own.