Kog'Maw Nerfs

I saw on the PBE there are some number changes to nerf Kog'Maw, however, I feel this is the wrong way to go.

Don't nerf Kog'maw's strengths, buff his weaknesses.

Heres what I suggest: When W is active (you can now unactivate it) Kog'Maw is slowed by 50% movement speed, the slow retains for 1 second after deactivation.

This would make Kog'Maw honestly balanced. Because this way he cant kite you or chase you down with incrediable DPS. Instead, he will punish you for ignoring him as it should be.

And don't tell me Kog'Maw cant kite, just watch this vid. (This is why he is so op) https://www.youtube.com/watch?v=JIU16N6usOg&index=10&list=FLrrQiq4kzJRblHE-4o8-4rQ