I didn't see an explanation of how score is calculated, so I'll ask if you have a link that explains it.
For example, my toon Painagain on Argent Dawn, ilvl 586 has a wow-heroes score of 8386
A guildmate, Halladay on Argent Dawn, ilvl 576 has a wow-heroes score of 8527
With 10pt lower ilvl, and both using AMR, a similiar gem/enchant scheme, how does his score end up so much higher?