From the gameplay, looks like Sturmtiger is a real killer. Imagine the tears of Soviet players when their cons blob gets wiped out by Sturmtiger, this tank put a middle finger to ISU in the squad wipe capabilities. This is how German do business with big guns.
Using one of these is a micro-intensive nightmare and it requires a lot of support. And if you don't nuke everything with it, you're helpless when there's a counter-attack.
As someone else said, its the ultimate trololol unit for when you want to put two fingers up to someone you've already stomped.
Then again, it will be fun to see how people adapt it.