Lets say you are plaing Cloth wearer, you get 1-2 ilvl 200 item to choose between from Emblems, Heroic Dungeons and Crafting gear, by having naxx 10 doable your gear option is increesed to 3-4 items to choose, with same ilvl but different stats. So if you have Dps with full ilvl 200 items but not right stats and u have a guy that choosed correctly stats for his class you will see differance in dps output for quiet a bit, i bet differance in dmg will be atleast 1k+ Demage per second.

