How do you avoid wiping ininstances?

[MongoJerry]

I did, that is part of the reason I was wondering about putting it on the pally.  Yeah, it is still all eggs in one basket, but that trick can be used after the soulstone rez to get yourself safe to then go and rez the rest of the party.  As tal mentioned, palys pretty much never have mana in combat and might not be able to pull that trick before hand.

There's also the fact that the soulstoned person can choose to rez while in combat. I've prevented many wipes after I died by rezing in combat and going right into healing mode. This can help when the priest dies early for some reason or as a way to extend a fight against a difficult boss. You start off with a pretty decent supply of mana when you rez. Also, sometimes I've managed to rez a person or two as well, since you start off not in combat after you rez.

Anyway, it's best to soulstone the priest instead of a paladin, because the priest is usually in the back anyway, so if they die, they're likely going to be out of range of mobs once they finish killing the party. Plus, you don't want to put all your eggs in one basket as others here have mentioned. I've met a lot of paladins who wouldn't have a clue how to handle such a situation.