Town is a major metropolitan city. The on and off bus lets you see the city and is worth the trip. Totally disappointed in the Raffles hotel w/its Singapore Sling drink which they sell for 20 USD. I'd skip it.
Definitely a place where you need at least 2-3 days. Add onto the beginning or back end of the tour but take the time to see all the great things about this city. Climb the great wall at a minimum