The last Cho'Gath change

As you probably know, Riot nerfed Cho's ultimate cooldown in 20 seconds, in exchange of half of it being refreshed in case of a minion kill and a mana refund as well.

I might very well be wrong in this matter (there, I said one of the 3 things you never should say on the internet), but I don't think it is worth it. Not calling it a nerf, but I don't think of it as a great buff. If anything needs a buff, I think E would be a good place to start, maybe giving it the Aatrox treatment for two different toggles?

With 40% CDR, the cooldown becomes 30% of the original if you eat a minion, which is approximately 24 seconds. (100%-40%=60% 60/2=30% 40+30=70% CDR). Pretty sweet, actually. But, I still feel like the 20 seconds were a little too much. Can you at least just change the rank 3 CD? Just by 10 seconds I would be happy. He used to be called a great late game champion. He should feel somewhat stronger in the end game, right? Even 5 seconds less would make me shut up, but 80 feels like a needless increase for Cho'Gath, taking in account several weaknesses that already make him quite hard to survive with. All I am saying is that it could be a great buff if the cooldown didn't increase so much, but, like I said before, I might very well be wrong.