Check out the LM forum.... There is a LM that healed BfE, a thread on LM tanks for 3 mans, etc. LMs are only as good as the person playing it. We ran 6 mans last night with a Cappy tank, 3 LMs in DPS, 1 RK heals and 1 RK dps. The mobs didn't even try to fight us, it was a bad night to be evil We ignored most mechanics and burned though everything.
The real question is the person a good LM. A bad LM is a totally wasted slot where as even a poor champ will contribute. Good LMs are worth their weight in gold. Debuffs keep the healers less busy, anti stun the heavys and healer, cc as required, heals, etc. In the moors as noted above they are a primary target of the creeps. Tells ya something there. In SoA days bosses could be CCed until a LM (Shauna) was soloing all the content in the game as a level 50 LM. Watching his videos is a treat to watch a master at work. While I can see what he is doing, it far exceeds my skill set to do it.
But, in the long run, it applies to any class. A person who understands their class and skills, will always exceed a person who depends on gear and some rotation they pulled off the forums. My .02
Used to show a pic... Seems to be broken links now. Good Ole Turbine.