I've played a few compositions now, and overall, yes they are:

  • very high burst dmg.
  • wear 2nd best armor in game - with shield in our configuration for even higher armor.
  • Can heal while in dps spec, and chain heal (arguably) second only to circle of healing as best multibox heal.
  • can res, and have wipe recovery (this is huge).
  • totems play to group "synergy" of mutiboxer (stacking buffs), and basically seal the deal (staggered tremor totems make them almost immune to fear, grounding totems shut down casters, earthbind totems mess up melee, fire-and-forget poison & disease answers, etc, etc).
  • and more
There are other groups that have other more specific strengths, but point-for-pound, especially for pvp, I just don't think you can beat it.