" Vel’Koz at least doesn’t seem to have hit the mark.."
"..with his ability to pull of a successful ultimate too restricted by the changes. We’re making some follow up changes to him as a result, allowing his ult to again contribute some stacks towards his passive."
I personally think he's hit the mark well with the last patch. Even if its not true damage, the ult can still be devastating at times. And even when you get the E>Q you can ult straight away without waiting for the delay and it turns into true damage.
But if you really want to change him a bit, may I suggest the SPEED at which his ult moves? Currently if the opponent flashes all the way to the side, they basically miss the entire ult except maybe ~.5s. How about increasing the speed at which the ult moves so that if the opponent flashes somewhere, they don't entirely avoid his ult (unless they flash behind him).
May I add-GOD it feels good when you can see the enemy's health bar just widdling away under your ult. It's like pre-nerf Kogmaw's W with guinsoo's.