To me, Challenge mode is a riddle, wrapped in a mystery, inside an enigma. I am hoping to recruit a few people willing to fight and mostly likely die...repeatedly to lift the aura of abstruseness.
Here are some of the facts about CM Dungeons:
- Your gear is down-scaled to 630. However, it is not up-scaled to 630. So if you are wearing a 615 piece it will stay 615.
- There is no loot in the dungeon. You will get some money and at Bronze the title: the Indomitable, at Silver: Challanger's War Yeti, and Gold unlocks some transmog weapons.
- Things that do NOT work in CM Dungeons: Gems, Tertiary stats, (speed, leech, avoidance), Runes, set bonuses, proc and effects off the ilvl 715 legendary ring.
There are a ton of fantastic guides for Challenge mode dungeons. I took a lot of information from this one: http://eu.battle.net/wow/en/forum/topic/16884607488
Seems like most people say that Everbloom and Iron docks are the easiest. Here are some guides for each.
- Everbloom: http://www.icy-veins.com/forums/topic/7850-completion-guide-challenge-mode-everbloom/
- Iron Docks: http://tankandspank.net/dungeon-guide-iron-docks-challenge-mode/
I'm a very lazy casual player, so I personally am not interested in trying to get silver or gold. Bronze seems doable, but overall I just wanna have fun.