Last I tested on k/r (which was a long time ago), none of the k/r elite skills yield bonus aggro.
Whirlwind shield has a x10 aggro multiplier, the highest multiplier of all knight skills. Truth shield bash is the highest dps knight skill and i *think* it has a x5 aggro bonus. Don't quote me on that though. The point being that those two shield skills generate the most aggro.
Whether its worth it or not really depends on how much damage you gain. You would need to actually make the weapons and test this out yourself...meaning how much aggro you generate using each weapon set to see if they are equal or not.
Unless you gain a significant amount of damage, it won't be worth it because you'll be losing your biggest Aggro skills. While being able to use a second hatred rune "appears" awesome, it only yields 19% more aggro (100% base + 136 from threaten +54 from 1 hatred gives 290~, 54 on top of that is less then 20% more). Not to mention that shields allow you to use shield of discipline and shield of valor, both very strong skills for survival. Lastly, remember that due to shield mastery, 1 shield gives you something like 90k pdef (30k base x 1.63 shield master x 1.65 Enhanced armor x1.1 pet def skill )...that's a lot to make up for in simply tiering armor.
This post has been edited 2 times, last edit by "BlankMinded" (Jun 15th 2014, 2:59am)