Though I've been playing this game for many years never played healer, so in my down time took one of my mid level shadow alts (got x2 alliance and x2 horde) and went Disco. The build (PvP wise) is extremely fluid and feels really good .. solid passive mitigation and high mobility with almost no cast time.
Disco is one fun build!
So, for any one who is used to playing a build that is always tunneled -ranged- and never tried Disco, go try it NOW!