Have been there done that.
Armor, and for a priest, our armor buff, makes a HUGE diffrence. I can survive 6-8 hits from a mob in UBRS buffed to the max with armor. Without I last maybe 3 and thats if he dont get a crit in on me. Gear makes a total diffrence in this game at higher levels, But if i was to do the experment in a newbie zone then the resuls are basicly the same, maybe 2-3 points diffrent.
So in my experiance, I can say that Armor make a diffrence and can consider this case CLOSED
For the Honor of the Horde