Been playing a ton of midlane Quinn, here's what I think of the pbe changes
I do not think they will not be good, allow me to explain my reasoning. First off, the changes will have some utility in bottom lane for skirmishes for sure. However, I find this runs counter to the fact that her ult makes her a fantastic roamer, but not a great traditional marksman. It's rarely viable to roam from bottom as an adc. Quinn will always be very weak 2v2 with the ultimate she has currently, because its not a fighting ultimate. This is why I find current Quinn to be a better fit for mid or top (with tp).
So we've established why Quinn is not a strong pick as a traditional adc. She might be 'okay' especially with the Q change on pbe, but with her ult it's very unlikely she'll be 'strong.' I'll now explain why the alterations on the pbe actually nerf Quinn in the respect that Riot geared her for.
Her waveclear goes down with this change. No brainer as to why this makes a good midlaner, I also find it to be very satisfying to cs with. You can do a neat combo with your ultimate where you Q after Skystrike and instantly clear all minions in the aoe. Very effective for large waves mid-lategame. Her assassination potential goes down with this change, which is a big deal if she is expected to be the roaming marksman. Her incentive to roam decreases as her ability to pick off low health targets does. The damage to weakened targets is honestly quite significant. Her harass also goes down, which is a shame as it was actually quite decent with the update. Watching your opponents health whittle down steadily with each throw of your bird is a great feeling. She will be weaker in all these aspects. Now on to what she gains from these changes.
She gets what looks to be a buff to her passive. It's hard to complain about this as her passive is a huge part of her damage. Both mid and bot Quinn can appreciate this change. On to the 'blind.' The value of this ability is decent but not great mid. As a solo laner you can't do anything meaningful in the time they are blinded. You can get an extra auto or two off. You can Vault auto. These things were quite attainable beforehand, without any pseudo cc besides Vault (which already set her up quite well for follow up.) Only difference is they can't retaliate quite as well for this period. You could, theoretically, set up a jungle gank using this ability as your opponent would be unable to react as the jungler approaches. That's not bad but it's not something to write home about. This ability could be strong in teamfights, but I don't see it being worth dropping all assassination from her kit. It doesn't look great.
I write all this because I am in love with the new Quinn; she's quickly becoming one of my favorites. I truly believe this new Q to be a downgrade. If I'm wrong about this than I'd sincerely like to know. @meddler or whoever handles this stuff.