So the ISUs shot has the exact same damage as the old one? weird...this is indeed a significant nerf... lol
HE as "standard" is the best option IMO:
1. There are much more targets to fire at.
2. Hitting infantry results in instant MP bleed, while damaging vehicles does not.
3. Your cons AT nades / mines can slow down approaching tanks, and the ISU has enough armor and health so it can afford a delay.
I for sure will use it with HE and only switch to AP on a situational basis ^^
yes i was thinking about this last night and you are right