It's not just a mindless slog from room to room either, as the dungeon we ran had a more twisted labyrinthine format. During each "run," certain bonus doors can be opened by a lockpick skill (rogues) or by dispelling an enchantment on it (casters) -- these routes often grant you treasure, but can also bypass rooms and lead to shortcuts. It's not required by any means, but having a well balanced team will grant you certain bonuses beyond just spells and ability synergy.
Having said that, you don't have to worry about fighting over loot. Just like Diablo III loot is "instanced," so you'll get your fair share of items. Gold works the same way, and I was told that this is clearly the case to influence cooperative play. There is still some form of competition though by way of a scoring system. Any gold you earn can be used to buy new items (like potions), equipment, and craft new characters.
