Currently, quests that are available on both Heroic and Epic difficulties are listed in the adventure compendium something like this:
Under the Big Top 5 (20 Epic)
I suggest that the quest actually be listed twice, with another line added something like:
Under the Big Top 20 (5 Heroic)
This would make either version easier to find.
It's annoying and time-consuming to have to painstakingly check ALL quests when I just want to see, say, level 22 quests, because some level 22 quests are only listed as level 10 quests. Oh, and so don't even sort right when I sort by level.