I wanted to book Mandarin Orchard but didn't do so in the end because of the service. I had called the hotel to make a phone booking for a venue but was told that I can't do that until I have met up with the manager. However, the manager will only be available one week later.
Well, as it turns out, another of the hotel that I was looking at allowed me to make a phone booking first and the manager was available to meet up a few days later. So I went with that hotel instead.
So if you are considering Mandarin Orchard, do take note of this procedure as many other hotels do not require you to meet the manager first before making the phone booking. =)