I'm a huge zed fan and I've only recently started to play him again after a long time (was getting another account from 1-30). Today I've realized that his ult got nerfed a few patches ago (you have to wait 1 second before you can go back to your shadow).
This makes zed barely playable. He already had enough counterplay with zhonyas/qss/exhaust. His level 6 powerspike was hard to deal with especially for a squishy apc or adc I give him that but as long as you played safe you were fine. He gets outscaled by most of other champions played mid anyway. Not to mention he does have quite a few counterpick matches in which he can't do anything (vlad, wukong, urgot, liss etc.).
In teamfights you can't do anything. You can poke but compared to like azir, viktor, xerath, ziggs etc. your poke is very mediocre. And if you try to get in you'll just get CCed and die. Your 1v1 potential is still extremely high (especially against champions that can't burst you down) but that's about it.
The only team I see him winning games is when he gets extremely fed.
So please revert his ult back to what it was.