As I find randart body armour not really competitive with upgradable GDA/RoR, I think maybe some possible new properties might make them more desirable. For example:
-bonus HP and/or MP (either fixed value or a percentage of current)
-torment resistance (not full, would be overpowered. Maybe 50%?)
-sticky flame immunity
On the other hand, perhaps accuracy and/or damage bonuses should be removed? Don't make much sense on armour.
Also note, I am proposing these for body armour only, not for cloaks, etc. They are competitive enough.