I would really like to take the 10-15 people in this thread saying that it is too easy to complete because people have done it in a few days after doing the quest line multiple times already and put them in a party and see how they fair with each part of the quest.

You could even have the unfair advantage of going into each instance with 15 people and would probably still have trouble getting past each phase in the time frame you are saying these people have done it in.