New Zac's Q
1st off, I've played Zac a long time, reached Rank 6 with him pre-rework (playing him both in top and jungle) so I knew the champion inside and out.
Out of his new kit, his Q is the only actual source of a problem. The ult, while odd and weird, is more useful now because this is a team game and not a 1-man-army game anymore.
I feel that if Zac can have the option to auto attack for the tether OR use a 2nd Q cast he would feel so much better. It's not hard to Q + auto attack, but it can be difficult to Q + Q because it's a skill shot making it possible to miss. So, if you Q + Q for the tether pull, I feel it should auto-pull both targets all the way together mid-way Nautilus style (which is honestly how it should be anyways instead of the pull stopping part way like it does right now).
Just a thought from an old Zac main.