@Riot, regarding possible Quinn changes.

What are you planning to focus on? She got a few weaknesses in her kit, no matter where she goes. Botlane her short range and risky E makes her suspectible to poke and hard initiates alike. Midlane her lack of effective/safe waveclear is notable as the enemy using abilities and not autos give little incentive to level up her Q. Toplane is where she has her greatest strengths, but the recieving end usually find the entire notion of Quinn top, one sided and anti-fun. She also have scaling issues, as she scale on bonus AD but have to favor botrk for it's dueling power. She's also easily itemized against as she only have physical dmg and no sources of magic damage.

I'll get back to her scaling, but first, her early game.

Quinn has one of the lowest hp5 in the game, given her short range which makes her suspectible to all kinds of ranged harrass, that gives her alot of sustain issues, given how squishy her base stats are. She also suffers a clunky aa animation, her auto attacks make it difficult to both attack move and apply her passive, as moving after firing cancels her passive proccing auto attack. Her abilities, while doing wonders toplane, are very lackluster botlane. Her best way to poke, her Q, is not a pass through ability. Graves and Sivir both have short range, same with Tristana and Kog'Maw early. Kog'Maws Q, Caitlyns E, Lucians W and R, Urgots Q and Ezreals Q are all the other abilities among adc's that can be minion blocked. Either said ability is a superior poke both damage and cooldown wise, or they're not meant for poking, but rather escapes, all-ins or dueling tools, and every adc here has other pass through nukes and superior range. Point and click harrassment such as Lucian or Tristana also have it's merits in lane, Quinns E is her superior trading tool, but to make the most out of it, she must follow up with autos to abuse her passive and steroids that follow. This kind of trade make her take substantial minion aggro, and her only escape besides summoners is on cd. So she has both inferior range and abilities to trade in botlane. Another thing is all of her skills basically being one point wonders.

Q blind duration doesn't scale.

W steroids are only triggered on her passive which has an independent cooldown.

E have poor scaling despite triggering her passive, slow is not increased and the CD is not something you'll notice in a hard engage from either side.

Max Q and you get waveclear, but poor steroids and a high cd E.

Max W and you'll have powerful steroids as both Quinn and Valor, but abilities tickle.

Max E and you'll have more opportunities to mark people with your passive, escape and chase, but zero waveclear, zero steroids and zero burst as Valor. This might be considered versatile, but the problem is maxing one ability over the others forces trade off's on ALL of her abilities.

In regards to her scaling, I have to say a thing or two about Quinns passive. It's a very powerful passive which scales extremely well damage wise. However, given the nature of her range and having to E someone in order to consistantly apply her passive it suffers alot from scaling issues. As an ADC, consistant damage is the everything, and her most powerful source for dmg output is random until you consume the passive one way or another and actively attack a target. It's ok in that sense, Vayne have to attack the same target 3 times, Cait have to auto anything 7 to 5 times. However, Quinn have a static cooldown with no way to reduce it and unless she uses her escape on someone, she has no choice on who is targeted. The static cooldown hurts her the most though.

Valor has his merits utility wise, through chase, escape, roam and assassinations. However, despite his steroids he is rather gimped in more than one way. He loses range, but that's not the main trade off, the main trade off is the loss of a passive. You could say his W is his new passive, but still, he's a fast melee character with no damage steroids, two damaging abilities and an execute which reaches it's full effect when the enemy is at 1% hp. The execute also scale horribly, it's a cool idea, the squishy adc goes into melee, dives the low enemy team with a marvelous high damage AoE execute. At level 18 Quinns passive deals more damage than her ultimate when targets are at full health, and an IE crit with a triforce sheen proc out-damage it at max damage. This just shows how hard her execute falls off. Valor has his moments as clean-up crew, but does poorly in full health all-ins, teamfights and suffers from scaling issues late game.

This wall of text is generally my thoughts on Quinn's weaknesses. I don't know how you plan to proceed with her, but I hope this lengthy post of mine will give you some insight regarding some of her stats, kit and scaling.

To round it off, I really enjoy Quinn, her kit is fundamentally fun to play and when she does well in a game she's a force to be reckoned with. I also want to mention that this thread is not about her bugs or suggestions on how to improve her, there are plenty of other threads for that.

This is a simple thread made to highlight her weaknesses and to hopefully get someone from Riot to tease about any plans that might come around.

Thank you for reading.