My humble opinion is that Rez should not restore any exp by itself. The XP penalty for dying should be partly (say 50% for discussion's sake) recovered upon looting the corpse. Rezzing could possibly damage to body and remove of the potential recovered XP, letting the rez get better with character level. This way, if anyone but the healer dies in a dungeon, the corpse run can be avoided but don't bother trying to find a rezzer to a dungeon if it's a complete wipe, it won't bring any more exp than walking back in. This also opens up the corpse run to be avoidable via a corpse summon that cost money and all possible recovered xp. So a party tight for time at the end of a night can make the call to corpse run or quit.