I box prot paly / 2 x Elemental / Shadow Priest / Balance Druid

When I need the healing I move one elemental to resto.

I like the mana return and health but I do box with a friend that runs prot warrior / mage and even with similar if not better gear I can't keep up with a mage using the shadow priest. So if you are looking for straight up dps having multiple shadows is not ideal, but then again it is a game and you should play what you like.