Quinn is my all-time favorite Champion even after the rework, but I stand by my view that removing the ability to play as Valor was a mistake. It's like removing Gangplank's oranges; you just don't -- it's core to that Champion's theme and a big part of what makes them fun, unique, and enjoyable. Before Quinn, there was no other AD carry who had a melee transformation as their ultimate. Many people claimed that kind of ult wasn't good on a Marksman, but I feel this comes from ignorance and a lack of practice with the ability rather than acknowledging it wasn't appropriate to use in every situation (diving into a teamfight was rarely a smart thing to do as Valor).
Besides, to quote Riot Statikk on the subject:
{quoted}Ultimates often "break" the normal rules of Clases and Subclasses, that's what makes them interesting and cool a lot of the time. For example, Ashe's R as a long-range initiation spell is not something we'd normally put on a Marksman.
This is why oftentimes some ultimates feel out of place on certain Champions (Shyvana is a Juggernaut whose ult gives her mobility, Katarina is an Assassin whose ult deals AoE damage and requires her to stand in place, etc.) Given this, I'm not sure why a Marksman who could temporarily become a melee Assassin was any less wrong or healthy than the above examples.
Now, I'm not saying Quinn was 100% viable before her rework or that she isn't strong today, because she is. I also don't mean to claim she was the epitome of gameplay health -- she definitely had some issues in regards to oppressiveness against melee Champions, and a feast-or-famine play pattern. But I refuse to believe removing Valor as a playable character was 100% necessary in achieving a healthy gameplay state for the Champion, or getting her to be the map-mobile character they wanted her to be. While balancing dual-form characters can be tricky, it isn't impossible, and I imagine even less so for Quinn who had closer to 1.5 kits than 2 (as opposed to Nidalee and Jayce who actually have two distinct kits packed into one).
What's worse is that she still has quite a few glaring issues that her rework was intended to solve -- she's still feast-or-famine, still employs an assassination pattern that's difficult to express skill with or respond to aside from dodging a skillshot, and still pretty oppressive against immobile melees that are typically found in the top lane. While I don't think a full revert would be appropriate, I definitely think some changes need to be made to land Quinn (and Valor) in a better place.