Most of my /click castsequences do about the same damage when casually spammed as when I panic and really spam my button fast, really the only thing I lose is some mana efficiency (over writing DoTs or Hots too soon primarily). That means when I fight normal mobs I do good damage, and when I fight a heroic boss and get too excited I'll still do good damage.
I used to have two different macro sets I would switch when doing bosses, but found out that just changing the spells in my healer's macros was so much easier.