What is the benefit/problem with having the same dungeon (i.e. Food dungeon) but 3 different difficulties?
Normal difficulty L/L/L
Hard difficulty E/E/E (double rewards from normal difficulty)
Insane difficulty R/R/R (quadruple rewards from normal difficulty)
This proposal would not only give players a little more rewards, but mainly would give us a reason to utilise our epics/rares in battle.
Most players would not be able to complete the R/R/R dungeon because their monsters would be too slow (even when equipped with speed runes) but the fun would still be there.