Quinn really doesn't need any changes at all. She's perfect. People just don't understand how to play her, so they dismiss her as being trash.
Anyone saying "Quinn is useless in team fights" or "Quinn is useless late game" is exactly the people I'm referring to.
She is AMAZING. You guys just don't understand her unseen power for winning games.
Look... anyone building BT and IE on her, change up your game. She is not really meant for ADC (though she can still do it) and you should not be building so much AD on her as it is purely overkill and not worth the cost.
I used to follow the popular builds with Quinn but they are all wrong. Now I'm winning a lot more games and getting great K/D/A every game. (just had a game where I went 19/1/6 playing Quinn ADC) I used to do average/sucky with Quinn because of an improper build and guides teaching the wrong way to play Quinn. But my game has improved 5x over with the changes I've made.
Never build BT or IE on Quinn. If you are, that's one reason why you are losing games. She doesn't need that much AD and it's just overkill and a waste of money.
Don't treat her like an ADC at all. If you are standing in the back lines trying to kite during team fights, then you are doing it wrong. If you are diving head first into team fights with your ult, you are doing it wrong.
I can play and win with Quinn as top/mid or adc. She's extremely versatile, never gets banned and rarely gets picked, so it's super easy to Quinn main because people underestimate her every single game.
You just have to deal with the fools who question your quinn pick every champ select.
"wtf, why u going quinn mid?!"
"lol quinn top?"
"quinn is bad adc why u pick quinn? get lucian or tristana"
"we need a tanky top, not adc"
"we need an ap mid, not adc"
Then I crush the mid lane so hard, carry the game, and most of the time I don't even get an apology after we win. Quinn life is a hard life.