Anyways, I have tried both the shadow builds and the electro and have come to the conclusion that both builds are equal, the difference is you playing style.
If you prefer to be able to hit big all the time, go electro.
If you prefer to spend three turns setting up to do gigantic go shadow.
In the end, both are equally powerful, just in different ways. Electro has charged blood which is what makes it awesome. Shadow has a number of DoT's that after set-up, make for VERY heavy damage.
However... For the time being, I recommend electro over shadow due to the bug with overdrive. Overdrive is what holds the shadow build together and it is one of the buggiest things in the game. If it works correctly (very unlikely) it balances the two, but as is, charged blood is not glitchy and is what makes the electro good.
THEREFORE, my conclusion is that while in a perfect, non-glitchy world, using either would be a matter of preference, but with the bug in overdrive, shadow is the lesser of the two.
Oh, and don't say, "But you just don't know how to play with shadow." That is completely incorrect as I have stated above. Shadow has potential, it is just that IMO the bug with overdrive makes the electro more reliable and thus better.