Originally Posted by
Abandon
Gearscore is the worst possible way to describe your gear to people though.
Fetish of Volatile Power is a horrible trinket for Shadow, and yet it has a higher item level than Abyssal Rune, and so Gearscore would assume that Fetish is better despite it being much worse. It also doesn't show any gems or enchants, or even if the gear they are wearing is vaguely appropriate. With Priests there is a limit to how far we can go wrong, since we can only wear Cloth, but if they have 5100 Gearscore in full PVP epics then I would say that would be a good indication on why they are having problems healing it.
Gearscore has a use, which is when you know nothing about a player it gives you the very basic information on their gear. Since it can't measure how appropriate gear is or if they have any idea what they are doing, it's better than nothing, but that's not exactly a glowing recommendation.