The item is going to be addressed in preseason, riot at the moment, knows that it has been too strong since the itemization changes at the mid-season mage update.
It is annoying being constantly slowed, but my central issue with it is that it is just a great item at the moment for any mage. There are very few mages that do not benefit from having it,
is probably the only one that I can think of at the moment that does not significantly benefit from the item.
As a melee top laner it is very frustrating dealing with
and
on a team, especially if they have a lot of hard CC already. I think it should slow, but the potency of the slow, the amount of ability power it grants for its cost, and the tankyness of the item are all problematic. My guess is that riot will decrease the slows duration and lower the ability power a bit to make it more inline with other mage items.