Re: the video... Having trained groups of 6-8 horde through BG's easily enough (pre-nerf), the thing which suprised me most was that within all the masses following that pally around not one priest or lock thought to drain his mana.
The variety or lack of defensive cooldowns at your disposal does nothing to diminish the value of having a permanent shield wall (60% reduction) that resilience can provide. As to the difference in health, you need to look at effective health. If you have 30k in PVE gear and 32k in PVP gear, at cap that 32k = 80k effective health, as that's the amount of damage it would take to kill you through resilience. So the tradeoff in this situation is not 2k but an effective 48k increase in health vs an increase in damage -- but remember that effectiveness of the % increase in damage will be greatly impacted by the resilience of your opponent.