Reminder: Quinns ult can't be used in combat or to escape combat in most situations.

What should be an amazing mobility tool is basically a +20 movement speed buff and loss of ranged attacks on a massive cooldown. Quinn's ult in combat is an all or nothing charge that uses her vault to attempt a kill, and if it doesn't work she loses her harrier speed buff and almost every cool down for a bad execute.

The execute values are complete trash compared to others in the game, cough (16% missing hp Lee Sin Q on 4 sec cd. OR Riven's 300% damage ult), the low base damage gets a 1% per 1% missing, at rank 1 it's max damage is 300 physical damage from a severely injured opponent.

As an escape it's basically 100% useless unless you begin using it before they are in combat range, which can be said for anyone with the ability to walk, period. If you enter combat as Valor, you are basically a melee champion with an enemy target dash and ALL MOVEMENT DEBUFFS all but snare you. The only catch to this is that you can use Valor to possibly get a better position for vault, but, really, an ULTIMATE?

TL;DR: If you are snowballing on Quinn you can assassinate bad people split pushing, or you can suicide dive and pray your team saves you. It doesn't come back soon enough for it's pathetic damage, the time it allows you excess movement speed doesn't justify its cool down, and finally, it makes you complete garbage trying to run away if any movement impair hits you since you lose your passive kiting ability.