Now that I have been getting closer to min/maxed EWH survivor gear on my sin tank I have been contemplating what expertise to shoot for and have been having a hard time deciding. I think I really need to parse some logs for a decent comparison to be made between removing a few expertise armorings for force wielder 27 armorings.
I am not at my gaming machine right now but I believe the difference between 1200 and 1380 expertise is about 2%. 2.5% over a warzone, lets take a high amount of dmg you are taking since you are guarding focus targets lets say 500k dmg taken. That would basically be a dmg mitigation of 10k - 12.5k over an entire warzone.
The question would be, is having an extra 2k - 2.5k health (color crystals - end and 2 armorings) helpful to give healers time to heal through burst of smash / focus fire etc. Not to mention everytime you hit overcharge saber you would get an extra 200-250 health since it is a 10% heal, over a warzone that probably won't make up for the 10k lost but I think it might help with the burst ability of smash etc.
Just a thought on what stat would be more useful past 1200 expertise, still need to test out both to see the difference.
Here's the thing though. The damage mitigation is not the only factor that comes into play. By giving yourself less expertise but a higher health pool, you are actually stressing the healers more to keep you alive. You've made your health pool larger, and reduced your damage mitigation. On top of that, the more expertise you have the more your allies heals will hit you for.