Attack Speed on AP Mord?

Curious as to what you guys think

since i vastly prefer going AP in most of my games, i'm curious if something like would be a worthwhile buy on him to make him get off his Q's faster, as opposed to grabbing things that only affect spells, also gives him an auto or two with passable damage when he blows his CDs

i think the main issue is what do you replace with it that won't hurt too badly to lose