I've used EventEmitter on a couple toy projects, but I've always assumed that's adding a bit more overhead to everything than just using callbacks. It's easier to read though and probably easier for someone else to figure out in the future. I've played with node.js libraries that have callbacks strung out over several files, so tracking down exactly where some behavior is happening isn't easy.

There are a few examples out there about using events/listeners, but I think there's room for a really good one.