I will be honest to you, to simply compare X7 to 1Z is just out of senses. Why ? Because they are not even in the same league or cost....now, comparing to AK380 or Copper will make more sense.
Innocent remarks:
-why should a valid comparison only use similarly priced items ? Who's making no sense here ?
-price is not linearly correlated with quality, to state the obvious (back to point 1 and here we have a full circle)
-while a more expensive DAP may show superiority in objective and costly specs (capacity, built quality...), it doesn't necessarily apply to subjective criteria (sound quality especially, which is very biaised by personal sound signature preferences).
With such reasoning, the next "flagship" DAPs (god I hate that word, it doesn't mean anything, it is just used to justify blind inflation) will be priced at 5000$ with no objective specs to justify it.
Let's wait for reviews and comparisons to get a better idea, although I'm sure people will find very "objective" ways to justify the 2000$ premium for 1Z vs 1A (beside the additional 128Gb and weight in copper/gold).