So basically is 2.63% more damage overall along with 6% more damage during burst better, or is 1.36% more damage reduction? It's a small difference and the choice probably depends on playstyle.
I'll probably keep the set bonus just because of how important damage during HA is. 6% more damage while bursting is really significant.
But realistic we aren't able to keep this buff up nearly enough to make this 2.63%. Our uptime, haste from gear and item level is lower. I'd say our uptime is about 70% of PVE. This means 1.84% more damage/healing and 4,2% during burst (let's not forget that all CC get to us during burst and 2 Piece nerf was huge and dispelable).
The way I see it, it's a simple matter of choosing DPS/Healing being tied to uptime versus survivability.
Do I see this right?
You already did 75% to get the 2.63%. So your number is final. Still, I'm not sure our uptime is 75% of PVE's... the number don't get lower enough to discart the 4 piece anyway.
But I'll keep an eye into it.