Thanks again for all the replies! I haven't had much time to read, think or answer until now because I am abroad on a business trip and have had limited (private) access to the internet for the last few days. Writing from the client's office right now actually.
Anyway, I'm leaning more and more towards hiring an agent, if I can find a good one. When I arrive in Singapore my number one priority will be to make a good first impression at work and learn everything I need to be productive as soon as possible. If an agent can reduce the number of things I need to keep in mind during the initial period, then he/she might be worth it.
SINexpat: I'm from Sweden, a country with a very different housing market -- with rent control, and legislation nullifying private contract in almost every instance. The shortages caused by rent control is probably the main reason why no one uses an agent -- there is no (legal) rental market to speak of! At least not a monetary one. You need to have connections, or luck, to find a place to rent in Stockholm.