This is going to be a bit sharp but I'm just going to throw this out there.
Anyone who cannot beat/deal with a Silver/Bronze Zed should not be taken seriously on topics about assassin balance.
His kit is LOADED with counterplay both in lane and out of lane and any player worth his salt (i.e. anyone who's played mid for more than 100 games after level 30) should have had PLENTY of experience facing/studying Zed's kit to know it can be counter played.
If you can't beat a Silver/Bronze Zed (which is what you're going to be facing in Normals when he's "busted" on the casual tier lists), then why should you be taken seriously on the topic of assassin balance?
I mean... the counterplay is in your face. Its right there. If you've spend even 10 games facing a Zed/playing as Zed you would know his weaknesses.
He has 20+ second windows in which he is USELESS in lane.
His kit is designed for 1 vs 1 in a game where Zhonyas exists and where the emphasis is on 3 vs 3s/5 vs 5s. He's mechanically UNRELIABLE.
Banning Zed is also the most ignorant thing possible.
He can be counterpicked... not just from mid but also from bot lane and top. Tell me one other decent Mid who can be counterpicked by a freaking Support.
If you can't beat a Silver/Bronze Zed on average after 100 games past level 30... then your opinions on assassin balance should not be taken seriously