Heroic Dungeon Feedback Wanted

We’re looking for some of your feedback on heroic dungeons since patch 2.1, specifically regarding difficulty. What heroic dungeons do you feel are too hard? What heroic dungeons are too easy? List some examples, provide info on specific mobs or pulls that give your trouble, tell us about the heroic dungeon you avoid and why, or give us a complete review of every heroic dungeon in the game if you want. Anything that helps us get feedback on your feelings of how fun, hard, easy, or rewarding they are.

Since a large amount of changes for heroic dungeons went in with the 2.1 (Black Temple) patch, we do want feedback to be specific to experiences since then.