Edit - I didn't word the title very well. If you're looking for as much mitigation as possible, then SoE is great.

Based on the findings from this thread that tested melee/ranged/elite reduce vs. affixes.

Melee reduction will reduce damage from the following affixes, as tested in the thread above:

• Arcane Enchanted
• Wormhole
• Vortex

That's it. I was under the assumption that all affixes considered "melee" would be affected by melee reduction but that doesn't seem to be the case. I know a lot of Woh users (self included) running with SoE so I thought I'd give you all a heads up.

edit2: Ran a few t6 rifts and I still used SoE a ton, especially against the rift guardian Perendi. I still use SoE as default and Harrington's as a swap-in.