The piats are actually very good for their price, and if you can micro well (i.e. if you're not axis only player), they can hit even light vehicles. Though researching weapon racks as soon as 222 comes out is kinda stupid, so you're right about it not being an option to counter 222 rush.
It bugs me that the fuel starved version of the German army can shit out a panther tank first, but that's about it. The units are all good, I just think they could come out faster.
They shit out some Panthers disgusied as M10 just to fool the Merican, so why not?
I am still waiting for the OKW Operation Grief doctrine, wasn't it famous enough to make one?