I don't think Zac's new (old) ult really fits his play style. Zac is all about controlling the crowd, not knocking them away. I like the multiple bounces, and the additional damage. But I don't like the knock away.
The "dream" engage for Zac is to sling in, slap two enemies together, then ult. With each ability, and with each bounce of his ult, a bloblet is created. So by the time he presses all those buttons, there should be bloblets everywhere. Then, as he is bouncing multiple times with his ult, it gives him a bit of move speed, which he can use to "bounce around" and collect those bloblets. And as he does so... those bloblets reduce the cooldown on his W, so he bounces around with his ult, simultaneously spamming W, for a really nice combo. That's every Zac's dream engage.
Problem is, that dream isn't happening. And it's cuz his R knocks the enemies away. So he does the combo just like I described above. The ground is covered in bloblets everywhere. But then he presses R, and instantly 90% of those bloblets are destroyed. His R knocks all the enemies away, in every direction. And as they are knocked away, they slide over his bloblets, which destroys them. Now Zac is bouncing around with his R, but there's few bloblets to collect. Also, enemies are now much more spread out, so even for the few bloblets he does manage to collect, it's hard to hit all the enemies with his W because now they are all spread out because his R knocked them all away.
ALL of the above issues would be solved is his R simply knocked them straight up, instead of knocking them away. I realize some noob Zac's may be using R as an "escape tool", to knock enemies away so the Zac can try to run. But plz, that's not Zac. A real Zac wants the enemies to stay clumped together so he can bounce around, collect blobs, and spam W's onto them.
Anyway, I wish Zac's R would just knock enemies straight up and not knock them away. This would mean fewer of his bloblets would be destroyed when he presses R, so he could bounce around and collect them, and thus be able to spam more W's during the teamfight.