I've found that with a midnight arrival (and I've had a bunch of those this past year into SIN
), it usually takes about 12 minutes and S$20 by cab to the SunTec area hotels and about 18 minutes and S$25 to the Orchard Road hotels. I guess you can use that info when deciding if you want to stay downtown. It is usually 2-3 minutes quicker heading TO
the airports in the early morning as you don't have to spend time driving around in the maze of roads to exit Changi from the taxi stand!
Another option you might consider is to stay the first night at the Transit Hotel inside the international transit area and then clear customs in the morning when you wake up. You can then ride the MRT into town which is the cheapest and easiest option IMHO. Only problem is if you have checked bags, you will need to tell the airline of your plans so that they can put your bags into storage overnight while you stay in the Transit Hotel.
"The A340-300 may boast a long range, but the A340 is underpowered" -- Robert Milton, CEO - Air Canada