Sleeping should not only be done to regain health, but also to regain any spells that you have casted, or gives you the chance to change your spell list if you are a spell caster(mage or druid). If you are like the paladin, it gives you the time to restore your hands-on-healing. There should also be a chance to be woken up by radom monsters with the chance depending on the area you sleep in. Inns should be the best place, but outside is my prefered place to rest.
