User blog comment:LegendSpartan1/Zac Rework/@comment-26005392-20150114053157

Zac is my #1 go-to jungler/top/bot supp (with the right person), and I consider him to be my best character.

In my opinion, the goal of his passive is to maintain a 4% heal return (losing 4% of current and gaining 4% equals out to a net heal of 4%). It punishes those who are over-zealous with his e-w-q-w on an attempt to gank without proper backup, since you probably won't be able to pick up bloblets (usually using around 12-15% of health using just those 4), and it rewards those who play defensively, and allows zac to punish more up front in the early rounds. Obviously later on picking up a spirit visage or dumping into the appropriate masteries will increase the heal rate, but that comes at a certain price, and a certain point in the game.

I'm not going to reiterate what others have said, I agree with them down to a t. The boost they gave to him in the last patch was just what i was looking for in zac. Now he can split up enemy teams more efficiently, and since his e also grants bloblets for how many champs you hit, and lets bounce lets you pick up the bloblets easier, he can sustain better in a team fight (if he needed anymore sustain to begin with.) The extra bonus damage added to his e was a gift, and I honestly didn't think it was necessary.

You're also missing the big plus about zac. He has 3 CC moves, 1 move that does % of health damage with a stupid low cooldown, and 2 of his CC moves are knockups, which interrupt channels, something lots of people don't consider.

Zac is op, just like any other character is op, with the right build and right skills. And I have yet to find another champion that engages from the jungle or lanes with the amount of cc and damage that he does and come out relatively unscathed (lissandra is fun but she's too squishy)