I used merc healers and tanks..i play a Ranger..druid..but i want to replace the druid with wiz and Shaman. Shaman make a better choice if you use a cleric merc.. so you have great back up heals ( a lot of HoTs ) and buffs and debuffs. I was three boxing last time i played and my 3rd merc was DPS or healer if i was on hard content. ( if your in a guild you can gate to GH and use portals to get anywhere..so less need of porter class.. but port classes are still awesome )