I can honestly see this forum in the future if Cho's feast is changed. I really can. Cho would be really Overpowered, and you can't say that he wouldn't. A fully feasted Cho is something to be reckoned with. Having to deal with one constantly would be rather.... bad.
I'm trying to keep Cho out of the spotlight because I actually like playing him currently. And I feel that I do well with him. I hate how people keep asking for buffs for champions I like, which result in them getting nerfed worse off then they were before the buff. I hate it, I hate it, I hate it.
As it is, in any sort of higher ELO game it is hard to maintain the feast stacks and still have it available to use without just disappearing for ~4.5 minutes everytime the opposition does manage to kill you. This gives them incentive to focus Cho'gath, because with an Atma's and maxed out feasts/warmog's and some attack speed, he is a true monster to deal with.
But the reverse would be to make Cho'gath so strong all the time that he would be knee jerk nerfed, or have the items he makes best use out of knee jerk nerfed.
He's a solid choice right now, the player has to focus on surviving as many engagements as possible once he starts getting his feast stacks building and if the player does so he is rewarded with a strong attack, high health tank.
The only change I would like to see is to have feast give different ammounts for minion, monster, and hero kills.