this is a quick tab of the benefits of the spellsurge enchant...
some facts:
-100 mana over 10 secs to each person in the party of the effective enchant.
-can proc once every 30 seconds.(cooldown of 30 seconds)
-3% to proc, still procs pretty much every 30 seconds.
so, once you have about 1600 healing you're beginning to get into the overkill zone, i personally think that between 1500 and 1600 healing and you should be fine, then you should start looking into other stat gems depending on class, spirit and mp5 as a priest, mp5 and spell crit and a paladin, spirit and mp5 as a druid and god knows what as a shaman, i dont really know what they work off of.