At the very least, they would have held out longer on the Eastern Front. The Tiger II was the king of the hill in tank vs tank combat, but for every one Tiger, the Allies could produce multiple lighter and cheaper designs. Plus, the thing had horrendous fuel efficiency. Maybe the war would have gone on a bit longer. But more advanced Allied designs, like the Centurion tank, would have spelled doom for the Panzers eventually. Especially after it was upgraded with the 20 pounder gun. (I've been playing too much Wargame ALB)