MMORPG.com Atlantica Online Correspondent Andrew Corupz writes this look at independent dungeons in NDoors' MMO.
Independent dungeons are basically a fun way to grind. Features that are unique to IDs require the player to strategize a little bit differently than in the usual dungeon. For example, you may only bring five mercenaries in addition to your main character, so ready your flexible mercenaries who can adapt to any situation. Additionally, knowledge of mob behavior will inform how to construct your more bare formation.
IDs also dole out a relatively high amount of experience points, compared to monsters of similar difficulty. Many will use IDs to help level their new mercenaries.