Are his settings out of date? If you could post yours it would be appreciated. And how much dps do you pull?
http://www.maskedarmory.com/anonymous-wow-armory-profile-313297.html
I main destro, talents are usually Soul Leech, Shadowfury, Soul Link, Burning Rush, Grimoire of Sacrifice, Archimonde's Darkness, Charred Remains
General: enable targeting and facing, racials on boss, use pot on hero, create and use healthstones at 30%
Class Abilities: Unending resolve my low HP 40%, use dark intent, auto cast soulshatter (coz lazy

)
Pet: auto summon demon (felhunter), auto cast doomguard on hero, auto cast infernal (boss & >= 5 units), only summon in combat using instant abilities
Talents: Shadowfury: cast when 3 units in range, auto cast sac, store second charge of Archi for hero
Destro: enable AoE abilites when 3 units, use DS on chaos bolt aura proc - minimum embers 1, Chaos bolt min embers 3.0, chaos bolt min HP 100K, ember tap less than 15%, enable cancel casting for any target unit HP 20%, RoF - on target - when moving, RoF everything in range (when moving), use havoc (auto) minimum embers 1
Everything else is off, if i am just afk questing then i will turn on movement, enable all the fears and probably turn on racial on CD and trinks if I have any equipped but the above is what i usually raid with and it works pretty well.
Looks like I am averaging about 45K over the course of the raid