LvB was a lvl 74 spell :PI never played at a raiding capacity during vanilla, so what classes that I didn't play did was mostly a mystery to me, but as I understand it, during TBC, it was essentially Lightning Bolt spam. If you had the gear to supply the mana, I noticed some would also use Chain Lightning on cooldown (a cooldown which Elemental no longer has anymore). Flame Shock and Earth Shock weren't really worth it. Earth Shock was the Enhancement Shaman's baby, and near the end of the expansion, keeping Flame Shock up as Enhanncemeny was finally worth it (Back then, WITH Flame Shock, Enhancement was LITERALLY nothing but Flame Shock, Earth Shock and Storm Strike, but Storm Strike had to be timed perfectly to maximize double Windfury procs). Lava Burst didn't happen until the Wrath pre-patch, and that's when Flame Shock started being used.
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That's because Earthquake's been nothing more than lackluster ever since its implementation. It needs to have a decent boost in damage and the ridiculous cast time needs to be re-thought. It's a tragedy, really.