Not really one is a spg and another a heavy tank. I dont believe the King Tiger is infamous or evan that famous as a regular Tiger, Sherman or T-34 are more famous than it.
Indeed, there's a huge difference in purpose between these two tanks. One is a heavy tank destroyer/artillery support vehicle, the other is a heavy tank. Both would dominate the other in their specific roles but would in turn be dominated when caught in a situation for which they were not suited.
I beleive each had the capability of destroying the other, the problem it there would be a failure for a fair comparison as they are designed for different purposes.