Sounds similar to our situation, agility stuff drops everywhere on heroic (it was healing plate on normal mode).. but our druid plays resto/owl and our shaman resto/ele so.. our hunter is happy running in full heroic gear while everyone else only completed their tier sets and maybe 5, 6 out of 12 of their other drops. We had three caster weapons drop this week and nothing got d/e or was just a sidegrade while raiding together since the beginning of that tier in a rather small roster.
But to be fair and looking at all other 10m guilds it's not just us but everyone. Maybe they should hand out disenchant-token and you can pick a loot for x shared items. Disenchanting a dozen feral belts on sinestra while still in need of some BiS healer trinkets (for the whole T12 content!!) just suck