StuG has no turret and only 30mm armour on the side, it will be very vunerable to flanking and smart tankers that destroy the tracks. It will never be a KV-1, but it will be frontally impervious to most BR1 tanks.
Well okay - fair point, KV1 has even 75mm of side and rear armor ( crazy Soviets ), but personally I believe a good player will not show his rear armor.