When in doubt with a tank I go full endurance, the extra crit and whatnot can always be gotten via use of lethal 40B mods and the like after all, but as they say your mileage may vary depending on your approach, for my tank I go endurance, but the validity of going crit is there as well. You want to be at a comfortable health though incase you arent full mitigation, if you are full mitigation/tank then go with what you lack the most I suppose