Quins ult is more like AS based version of Riven's ult(Attack Speed and and Move speed instead of Attack range and damage), complete with an aoe execute that scales based on missing HP. AS is just much weaker in the early game on champions who don't have passive that exploit it, like Quinn. So her ult feels a lot weaker than Riven's unless you pack a lot of early burst/crit or you get fed early on. Then her late game options are building around the burst damage(makes her feel like an markman/assassin more than a marksman/fighter), which is good for Quinn and only okay for valor since he can't use his own passive or building around the AA, which is okay for Quinn but much better for Valor. I'm still a firm believer that she needs something passive to solidify 'how' she deals damage, along with the QQL changes we all mention constantly.