I think it's safe to say that Rengar needs that new Q back
https://i.imgur.com/EKscgao.jpg
His winrate dropped by 7%
After playing him his biggest weaknesses now is the early game clear, his Q being a single target ability limits his previous AoE damage he had.
In addition his Q could of been used as a get away tool, now he's just really immobile with no escape once he engages.
I'm no Rengar main but I realized that this made him worse.