I just got a coaster brake bike, and it's the ****.
As I understand it, a coaster can fail on a long descent where you ride the brake, so if you live in a hilly area then get a front brake. I live where it's pretty flat, so I roll cable-less. Looks soooooo clean.
Be careful though, you'll get hooked on skidding, and next thing you know you'll be dumpster diving for new tires.
There's a thread here somewhere where a guy named jimv goes in depth, find that.