I have only listened to the 30.1 and 30.2 non-XD. No experience with XD. The 30.2 sounds more open at the top with better clarity and detail in the midrange and treble. Personally I prefer the 30.2 over the warmer 30.1 which I thought lack airiness in the treble. However, there was a 30.1 owner who upgraded to 30.2(non-XD) and found it to sound too bright for his listening preferences. To each his own I guess.
The C7ES3 XD is said to be the star of the XD line, sounding more open and balanced than the older model. M30.2 XD should sound slightly brighter and more open at the top, just like all other XD models which have been tweaked to sound like that. Few P3ESR XD owners went back to the original P3ESR as they found the XD to sound too bright.