I tend to not compare units in a vacuum. Their IA dps is probably the same in average but they don't belong to the same faction and not facing the things. I'll not say that gut feeling is better metric than average but there are hidden reasons you don't see the IS2 as often as the Tiger nowaday even if their average IA dps are the same.
So, even considering there are less Commanders with the IS2 than there are with Tigers, this doesn't work as a single explanation, there are a lot commanders with few specific units that are seen a lot more than IS2.
Alright I don't mean to derail the thread here but since I already said something on topic I hope you'll oblige me.
Anyways, I know British people and others outside the US say IA instead of AI for bots (Intelligent Adversary VS. Artificial Intelligence) but what do you mean using IA instead of AI when referring to performance against infantry? Anti-Infantry versus what exactly? Infantry Attack?
United States