Neratho said:~850 is not huge burst if 2 spells have to crit (each ~11% chance).
The problem with shammies is that there's a lot of tools they get later on, such as WF or the reduced cast time on bolts. In my opinion, Ele can work out if you stack SP as if there's no tomorrow, but Enh without WF is like a warrior without deff stance. If you want to DPS - roll another class imo. If you want to play shaman - roll resto.