no, it's AP round is laughable. Bounce shot RNG for 8+ second reload. Could just get 2 SU-85 instead with more penetration, faster reload, and double the damage.
It needs penetration of 280 or something so that it's shots actually count against mediums.
No it does not.
Just get two SU85s if you have problems with ISU152.
For the sake of balance ISU shouldn't be units with huge range with great wiping potential and with awesome penetration. You can't have everything.
Right now it has great range, great AI and very decent AT. You are supposed to get other AT units if ISU is not enough, not just one units to counter everything. If you want to keep great AI, then AT has to be decent at max (which is). If you want better AT, then nerf AI but that would overlap with SU85.