This is a good fun instance Dan - plenty of things to kill, lots of opportunity for healing and its fairly lengthy.
I would put aside a couple of hours to complete it fully.
To complete HM you must kill the last boss without killing any of the bugs in his room - they have about 100 morale and there are around 20 of them so no aoe, no reflect damage and no auto attacks.
If you complete it, the coin for the non-set radiance shoulders is yours for the taking.
I can write a walk through if required - not done one yet as it is quite long.