80/80
But, on topic
You're bad if you think he's overpowered. He's not. CC still kills him. 100-0 burst still handles him.
I played against a 25-5 Yi and 1v1'd him with a 7-0 zed and 100-0'd him with enough time for him to alpha strike me and hit me once.
Malphite laughs at him. Shen laughs at him. Darius laughs at him. Riven laughs at him.
He's good, now. Finally viable. But it's amazing how a champ gets pushed out of mediocrity and into usability and everyone cries "OP OP!"
For the record, here's how to handle Yi
If he's jungling, don't be stupid. If you feed him, obviously that will make trouble.
If he's laning, lane swap someone who gives him trouble if you weren't smart enough to hard counter him anyway.
Late game, don't bunch up and then wonder why alpha strike chunked you all, he crit'd your carry to death, then just alpha striked until quadra. Space a bit, but still keep good positioning.
Late game, don't duel him if you can't for certain beat him. If you start to fight Yi, you're damn well not running away if you change your mind. This is probably one of the things people are crying over, but it just comes down to not being stupid.
Late game, send tanks, bruisers, or assassin's with more burst after him. Not a carry. He'll laugh as he gets 450 bucks and a bit more map.