Zac can only support now. His top and mid died with the change to his Q and R. His jungle sucks now because he has so little damage, he just can't defend it when it is invaded. The only role Zac has left is support, and even that isn't as fun as Top, Mid, or Jungle pre rework. Other then laning against Caitlan or Thresh, I have been doing really well in almost every game as support on Zac. That is, until you hit teamfight phase, then remember how much was lost with this rework.
If you want to see exactly what I have been doing, you can watch my stream as I am only playing Zac support now until Riot unguts him.