I swear by my Exile running Ubers. I carry the max resists from charms, rings and ammy(metalgrid) but no overstacking and I have no problem taking down meph with my Salvation aura. IMO the life tap from Exile (and Drac's) is as important as the resists. Yes the resists must be max (in my case 80 fire, 80 cold, 90 lite and 75 poison) however, I don't feel it's necessary to overstack when you have Salvation.