It's good against vehicles, but only some vehicles where the high armor is helpful. The reload is 6.55 seconds and the Penetration is only ~165 which is horrible and above average respectively.
I don't think it's terrible but I think it could have some lateral adjustments so it can find a niche where it fits better.
Making it more like the Comet or Panther with increase price and performance would probably be the easiest way to provide a more interesting choice for USF players. If you leave the Price as is it's probably going to be overshadowed by the AI sherman or the AT Jackson if its performance is "Balanced"
E8 is good.
Just that the stock Sherman is better AI and Jackson is better AT, so it's not worth a doctrinal pic unless you want to use it, since doctrinally you could get a Sturmsherman, Pershing or Rocket Artillery.
The sole vehicle that this unit is effectively better at countering than the M4A3 is the Panzer IV, which it will still fail to consistently penetrate at realistic combat ranges. Because it has a far lower ROF it is worse versus anything with less armor, like a Stug, and it has worse mobility to boot.
And the AI is not simply "not as good" as P4 or M4A3, it is horrible and barely beats out the Panther in tests. This is not the mark of an effective general medium tank and I am bewildered than anyone would defend this thing for anything other than being able to tank a single extra shot (80hp, so from almost anything: snare, mine, hhAT, etc)
I am going to remove spoilers from the images so people are forced to see them and say this is good performance..