http://us.battle.net/wow/en/blog/7628989
going through the coments, it seems most people don't really like it.
casuals want the gear, but they know they'll never get it. hardcores think it's a waste of time that will not help them on the progression race since the gear has no stats. both sides seem to think it's too much work, though they do for different reasons.
According to Lead Encounter Designer Ion Hazzikostas:
I think Blizzard overestimated the amount of retired hardcore players around lolOriginally Posted by Blizzard Entertainment
don't get me wrong, I love this game. But I didn't really like challenge modes. I am on the casual side: I really really really wanted to get that illidan set, but I'm just not good enough, and it makes me unhappy and frustrated.
inb4 "it's optional": no shit, something is optional in a videogame