I find WAR's do better at aoe tanking, as Flash's effects are dubious at times under the best of circumstances, as are the effects of Circle of Scorn. PLD's are more healer efficient, their damage mitigation translating to more efficient spells for the healer, and generally make better single, large target tanking easier.

In the end, they're about neck and neck, although this is the first time I've ever heard that PLD's damage output was higher than WAR's. Shield Oath is generally a staple in groups not for the threat generation (although it helps considerably, especially for fighting for area threat), but that incidental healer efficiency.