Researching it got cost increase and it got tremendous cost increase, it was bit more expensive, bit more durable AT oriented Greyhound.
You could actually rely on spamming them to fight Ost P4s, OKW P4s and up still rolled over it easily.
They didn't roll over it and I'm sure of that as I always play with AC.
They were way to expensive (360 MP for brit is really something) to 'spam' them.