Twitter Bootstrap or Zurb Foundation

So this is an internal battle that I'm having within myself. I have extensive knowledge of both Bootstrap and Foundation. I can't decide which one I like more and I would like to get your opinions...

Both have many of the same pro's as they do cons... is this a case of personal preference?

I believe bootstrap has more built-in javascript functionalities which is where I think it is set apart.

What is your preference?