depends by group composition.
overall i say HoR heroic. but after about 30 full runs and 40+ 2 first bosses kills ( in past i suffered final escape with all melee), it s not so hard.
i hate vehicle part in ToC, boring fight with horses. a waste of time and just 3+2 emblems.
in past i said same thing for oculus.
now oculus is best instance in random: 8 emblems, raw gems for 5 chars and a 15 minutes mode without looting. and using red drakes save me from special bindings and macros, so a welcome-instance in random.