One reason to use ULWD elements (the curvy one in the first post of this thread) that hasn't been mentioned in this thread is that they won't break if fired up "dry" (not immersed in water).
When a regular element (like the straight silver coloured one in the first post of this thread) is fired up "dry" the element will pop fairly quickly (usually before you notice your mistake!) as there is no water to dissipate the heat. While nobody means to fire up an element by mistake, mistakes do happen. Using ULWD elements provides you with a little bit of insurance against these human errors.
Popping an element is about the last thing you want given that you've likely already milled your grain and have everything ready to go.