succor kinda sucks, dude. even succor + WD isn't anything special. WHM are by far the better aoe healers -- it's just that one of the problems right now is that much of the real endgame content lacks heavy aoe damage, so WHM don't seem as immediately necessary. titan HM doesn't count, and much of coil is single-target healing unless you're hitting the enrage on T4. if new turns come in 2.2 and content is introduced which necessitates heavy AOE healing, WHM will again be in the spotlight.
*edit* before i get jumped on i don't REALLY mean that succor "sucks." i'm a scholar. i love it for obvious reasons. i'm just saying when you need to get EVERYONE back up from low hp, that's a job for WHM. i can do it, but not nearly as quickly or efficiently.