User blog comment:TheTobarMethod/Do AP's Need A QSS Upgrade?/@comment-4921386-20130903232439

Most of the infrequently used AP carries fall under the category of "burst mage." Save for a few other secondary applications, most of these casters are designed to simply dump a rotation and delete a target, and then sit and wait for cooldowns. For them, getting CC'ed isn't nearly as big of an issue as it is for ADC's. Traditional AD carries need to be consistently attacking in order to rack up a respectable amount of damage, and in order to keep themselves topped off and in peak fighting shape, via steroids or whatever. For an AD carry to get crowd controlled, their damage output hits the ground and they get blown up - they've effectively contributed nothing to a teamfight because they were unable to attack for 1-3 seconds before they were killed - QSS helps alleivate this pressure and enable them to peel off some of the focus drawn to them. An AP carry, or burst mage really, can dump their full rotation in less than a second, and then their overall contribution to a teamfight is pretty much done. Combined with their neglible autoattack damage, and their higher-than-typical-AA-range spells, crowd control is a significantly lesser issue for these champions. What really holds these champions back in becoming more common picks is generally along the lines of reliability (Multiple skillshots required to reach full damage potential), lack of mobility, lack of utility (You can nuke one person... and that's about it), and stemming from these, a low contribution should they fall behind. This is a flaw within the overall class itself, not so much the itemization - Burst mages offer very little counterplay because they can dump their rotation so quickly, so their kits have to compensate for them being able to delete a champion from the game near instantly.

That said, your proposed item isn't a very appealing item for most APC's. The health is nice, but not a typically desirable stat, and the 20% CDR is likely in excess of typical items (Athenes, Elixers, DFG, etc.) and blue buff. I can see this being useful on someone like Kat, but then again, so is QSS.