So since there is a big buff to the artifact shit and it's last chance to get the mage tower shit done what do you guys think is the best to focus on? I have completed Warrior, Mage, and Death Knight. But I have DH, Hunter, Priest, Paladin, Lock, and Druid at 110. I really doubt I am going to complete all of them for every spec but if I was to prioritize some what will give me my best bang for my buck so to speak? I am thinking the Druid since it's the biggest appearance change. I could level up Rogue, Monk, and Shaman and try and gear them but I don't know if I really care to bother at this point.
On the corresponding ones I have done (all ilevels ~930),
I had the most trouble with Guardian, even while using the chest lego (which is purportedly the best one for the challenge). Prot pally was the second most difficult. I was able to complete the Blood DK challenge on the 4th or 5th serious attempt, which made the hours spent on the other two, that much more frustrating.
On the flip side, any of the Agatha (Feral, Outlaw, UH DK, Fury, Fire, Ele) challenges should be a cakewalk when the command center is up, since you get the buff.
The Warlock ones were all fairly easy, with the proper strat.
Destro:
Feltotem's Fall
Affliction: Sumdain has a post here, with tips on the fight, from a few months ago, and this on wowhead
Thwarting the Twins
Demo: Sygrin - DPS challenge with hardly a burst DPS check, gg. With demonskin and lifesteal to top off, you can survive multiple mess ups on mechanics.
Ret Pally was easy, since its also Sygrin. Didn't do holy.
Havok DH is easier than Frost DK, imo. I hear Vengeance is second easiest tank, but I think it's ugly, so never tried.