IS-4 and ST-I: worth the grind? in Russia Posted December 11, 2014 They announced a buff to the IS4 and since the IS7 didnt even need a buff and it went from 240mm cheeks to 270mm [From TD`s penning it to nothing in game] and fro ma major facehuf weakspot to nothing, im guessing IS4 will become a beast. I mean its clear the IS7`s real thickness is 120mm lowerplate and side skirts are 10mm vs ingame 150mm and 30mm. I`d say they will go very far to make the IS4 feel "New" again and its a safe bet it wil kick ass. That said, STI already does.