I've been testing rogue's expose armor talent on training dummy's to see how much my dps would differ from using it in a rotation, but it didn't effect my dps at all.
I'm just auto attacking with an armor exposed and non- exposed dummy and i get the same results.
When i let the damage meter run for a minute, i also get the same results.
I tried recount and Skada and I'm not sure what's going on here.
Were you attacking the lvl 83 Dummy? Yes, dummies have armour.
Also use a weapon with a smaller weapon range and take off any gear that could cause a proc to see a more accurate result.
Expose Armor does work, and it's one of the debuffs that mandatory to have in a raid. You should be on Expose Armor duty in raids unless another rogue is, or there is a warrior who can be relied on for Sunder Armor.
I haven't tested it at a lvl85 dummy, but I want to try that tommorow. What i did do was test it on the lvl 70 and 60 dummy's so I couldn't miss any auto attacks. I used dual daggers and did not waer any procable gear or poisons. I used glyph of expose armor and tested auto attacks on the dummy's for 42 seconds; both with and without the debuf and the results were almost identical, meaning that the dummy's that I hit didn't care about the expose armor debuf.