Congratulations, Luden's Echo is already more toxic than DFG ever was.
Just played a game against a Nunu mid and it was completely unfun. Yeah, the item might be balanced for high-tier play and, yes, I can figure a way around this specific mechanic, but there's zero entertainment value there. Every single time that AP Nunu has been good, he has been toxic as hell, same with Alistar. That's because tanky bruisers with sustain are supposed to have an inherent weakness: lack of burst.
Welcome to the world of 100% pick/ban. Bleh.