Survivor's Instinct is kind of handy to top off your hit points when you return to base to drop off loot, etc, but is not really necessary. It was pretty much the only healing I required in the wastelands (I had all kinds of restoration potions stored in a chest unused).
If you are doing a lot of summoning, resurrecting or are using scorpion traps, then Aura of guarding will let you take them with you (though with less experience if they get the killing blow).
