Good & bad.
good - it shows mood of the environment if properly shot
bad - color not balance & don't look nice & especially if u are shooting a serious theme, eg. wedding, its best to manually adjust wehn u came from outside into the church.
The way to manual setting WB is point the camera on a white surface, an example will be plain A4 white paper, & I mean really white, not grey nor anything. Adjust your cam setting to Manual WB & within seconds your cam will read the light temperature, there u go, a balance color in view!
I don't recommend auto WB because CCD sometimes don't get the correct light setting.
White balance must goes with the present light situation, eg, if u go into a room with yellow light where everywhere is so yellowish, by using above method(point on A4 white paper) will make the yellow become slightly whitish, then it doesn't look original.
White balance, man or auto? 
Linear Mode
