when is the last time you slept in a bed? i am not sure if i ever did this map.
i think sleeping in a bed should give your character a status effect when you log into him based on how long you have been logged off (with a max of course). This would give beds a benifit and people would actually use them.
there were rumors about new items in the beta server that would give exp even while you were offline. you could make the bed do that based on its quality, or just give a status effect like temperary fep % increase, % exp increase etc depending on how long you were logged out for (with a maximum).