Many will disagree with me, but Zhonya is now a much better purchase
Yes, it lost AP. Yes, its active has a higher cooldown. However, the fact that not only it has a lower price, but also a better build path - I can buy a Seeker's Armguard and then another amplifying tome (which I can then upgrade to a Fiendish Codex, making the final combine cost even lower), which helps especially if I am behind - means that this item is much less awkward to buy. No longer, when behind, I will have to farm and hope that I can get 1250 gold for the NLR then spend another thousand gold just to complete this item. Did I mention that it has cooldown reduction now, too?
While one can argue that the nerfs to the AP amount and the higher cooldown were unecessary changes, this item is, in general, in a better state than before. It is not the perfect solution to the lack of itemization for AP mages against AD assassins, but it is better than before.
as well as many 80 AP items like
and the new Hextech items.