Well, the good (or bad?) thing about having a cable is your
speed really depends on the number of people wired up in your
building, as they all share one cable. But that's about it. If
there aren't many, then you'll have a very enjoyable surfing
experience at high speed.
As for ADSL, they have a dedicated line from your home to the big
pipe (which connects you to the internet), where they will then
share it with all the rest in SG. So it'll still be jammed.
But if speed isn't too much of a concern, maybe just go by pricing
and see who offers a better value in terms of package?