METALLICIZE now increases base health and bonus health proportionally, rather than all increases being considered bonus health. For example, if you have 1500 base health and 1000 bonus health, the empowered cast will grant 1500 base health and 1000 bonus health instead of 2500 bonus health.
Active no longer scales with Stoneborn Pact mastery 2017.png Stoneborn Pact or Nunu Nunu's Consume.png Consume Well Fed buff.
Juggernaut item.png Cinderhulk's +20% bonus health is now only applied once after METALLICIZE, rather than METALLICIZE first increasing the champion's health already factoring Gargoyle Stoneplate active and then Juggernaut item.png Cinderhulk triggering again to increase the new amounts of bonus health.
Straight from the wiki... Nerfs to gargoyle stoneplate.
Chogath gets a minimum number of stacks from the jungle (and is by no means 'insanely fast'.... hes got a par clear speed for multi camps. Solo camps are slow until post 6 when you can execute them) and any more from champions.
I think the problem is cho-gath is a raid boss, and you are not countering said raid boss and ALLOWING him to get in melee range of you... because newsflash; his ult is melee range. Yeah sure 2000 true damage with 8000HP yadda yadda but thats VERY late game and he probably flashed on you to do it or you allowed him to get close enough to EQ you.