Let's Talk: Quinn And Her Bugfix.
WARNING: This thread contains OPINIONS on Quinn's current state of power. I am by no means a master at her nor am I good at the game. These are just my thoughts from my experience with her.
So, as you know if you read the Patch Notes or have played Quinn recently (She's free, you have no excuse to not), you'll know that Quinn got a significant bugfix + tweaking.
Firstly, Blinding has been tweaked to, essentially, ignore autoattacks like it should have in the beginning. It used to sometimes not block some autos which caused some real rage of "WTF, how'd you auto me, you were blind!" This also affected Teemo's Blind, by the way.
Secondly, Quinn's E now places her correctly on the edge of her AA range. This is monumental, since pre-fix, she would usually be dumped between 25-125+ units outside of her range or it wouldn't react to terrain like it should (Like bouncing off walls instead of going over, etc).
Now, Quinn is what she was always meant to be: An ADC meant to counter right-clickers that blows up fairly easy and can switch, using her ult, into an incredibly mobile melee attacker with modified abilities that are more oriented to jump straight in and walk out laughing at the pentakill'd enemy team.
However, I speculate that she might be doing her job almost TOO well. While she probably isn't high on the priority list, I think she needs to have an eye kept on her. Her Q does great damage for an AoE Blind, her W is one of the best utilities I can think of for counterganking or scouting for Dragon and Baron, her E is sooooooooooooooooooooooooooo good, and her R is fun and crazy strong.
TL;DR: Overall, she's my favorite Marksman by far and is actually good at pretty much every role, but excels at top and ADC. Her jungling is pretty strong because of her passive, Q, passive W (AS steroid), and her ability to proc her passive twice with her E. Right now, she's in a great spot and is pretty healthy as a great anti-ADC, but suffers against casters that don't have channels. I don't expect her to be seeing the nerf bat, but I would appreciate Riot to keep an eye on her in case she gets too strong.