I would take a HoZ over exile in pvm everytime unless you don't have dracs and you need the lifetap from exile. Having 40k defense isnt necessary in pvm. HoZ has the huge resists and +str and +vit. In pvp I would take a HoZ about 90% of the time. The times where exile really shines is when you are dueling a barb or something where the 40K defense is necessary. Everytime me and my friends dueled our fully equiped smiters HoZ always came out on top.
for pvp ipt smiter is not viable imo
fo pvm 1 pt smiter should use hoz since hoz provides pretty good resists when um'd.
Your smite dmg comes from the weapon however not the shield. For ubers best weapon to use is LW, for general game play use grief