The thing is getting the balance so that resting in the tent doesnt punish the party for wanting a 10-30 minute break from sp/xping without making it mandatory before starting a adventure. The way i imagine it is you get a signet/sigil like effect that gives you increased stats and sp/xp gain determined by how long you spent resting capped off at a certain amount of time. The increase wouldnt be enough to bridge the gap of sp/xp lost through resting but then if you add facilities into the camp to help players restock and replenish their gear it might be atleast be desireable enough to take a break every now and then.

Also if this sort of thing is implemented would be nice for a minigame that players can play with each other rather than just the npcs =) like.... say tetra master.