-streets are not as clean as expected, especially compared to Tokyo, which is a much larger city. I lived in Chinatown in the People's Park Complex with 6 mainland Chinese (I'm American), which was an interesting experience.
-the expat community is dominated by the finance community, which can tend to limit the crowds you will run with if you're not in with the locals. I tried to befriend the locals, with limited success.
-it doesn't feel like the police state it's made out to be, don't worry about being arrested for chewing gum (I saw some T-shirts with a "Legalize It" theme referring to gum).
Overall, Singapore seemed sterile to me. That was part my reason for quitting my job and moving back to Tokyo in April. I like Singapore, but not my cup of tea. Maybe that's just because I'm a huge fan of Japan.