Basically what you're asking is damage vs survivability
with a high +str plate, you will take more damage from melee mobs but kill them faster. With a high ee plate, you will take less damage from melee mobs but kill slower.
Keep in mind an ee plate will do nothing vs a monster doing a crit, or a monster doing spell damage to you.
It's your choice really - and also depends on how much stats or ee you can get on it the item.