Party of 6 will trivialize the content. This is a point that has been made, and refuted with "so what"..
It has also been refuted with "implement split exp," which (since the exp forumla can be freely modified) will basically by definition be able to balance the game.
But also, yes "so what?" Does it affect you if some people turn on a toggle to play an easier game with a party of 6?
...and it's got nothing to do with me. I merely pointed to something that's been pointed out in the thread. By all means, turn the game down to Casual, and use however many comps you think you need to complete content. I really can't begin to explain how many F's I don't give. What I will be doing, however, is looking back on threads very much like this one, and this one, when people start complaining about the game being too easy. For me, in the current difficulty, a party of 4 is already trivializing some of the content, I listed the tutorial above. I won't be utilizing any options for more. Why would I, I'm finding a lot of this mind numbingly easy already. I expect that most of this will be countered by having difficulties added however.