the X10d is a line conditioner, it sorts of compensates for the RLC components in a line, resistance, inductance and capacitance properties.
Well, it does improve the sound especially on the mids, when used with low end sources like mine .. *sob sob*
but if you were to use it with high end sources, I don't think you will notice much of a difference.
the XTone adjusts the tonality of the sound, to increase/ decrease the level of bass and treble.
Just me,
Fuh Siang