It is HORRIBLE to have a maxed player on your team unless they are the most focused and are keying. Otherwise, you have to keep bugging them to open skill doors, and a slow maxed player can add 10 minutes to a dungeon time. I can only remember one instance (in 21m DG xp) that not having a maxed player hurt the floor, and that was when a single dead door (one nobody could open, even with potions) blocked off every bonus room. Regardless, we finished the floor in 19 minutes and got about 2/3 the xp. Communication is probably the biggest obstacle in dungeoneering, and voice chat makes this much, much better. For a perm team, it's pretty much a must.