Ilv gear is irrelevant for 2 classes. Tanks and healers. I say this because I earned most of my gear barding and then bought stuff for my mage.
So unless its their only class ...the ilvl of gear doesn't necessarily mean they are an expert at that class.
That being said garuda is a test on the whm to see if they can manage their mana, which sadly doesn't regenerate very fast. I have yet to go back and attempt a run at garuda....kept forgetting to use the 30% increase button, which would have helped considerably in healing.