Oh what, CoShadow doesn't count as a button now :-P
Although I seem to remember at some point fire destro began to outstrip the SB spam (meaning you also used Immolate!) for personal DPS, but you still needed a few shadow spammers to optimise the mana batteries.
We also had a spec that used Nether Protection, Shadowfury and spammed SoCorr to tank the imps on Illhoof.