would suggest you check out my review of the XO1-D2 on dagogo.com, but i also have the EMM in. granted, its only 12hrs on it, so prelim impressions are just that (and i'll write a formal review on dagogo in which i compare the two). very quickly, the XO1 has a more firm foundation and better dynamics, not to mention build quality that isn't just 50% better, but 500% better. that said, the EMM doesn't sound like digital...its more resolving (the most resolving digital i've heard), eminently musical, and is nigh on the sweetest player i've heard (doing wonders for bad recordings).
quick thought: if you've undynamic speakers (planars / stats), i'd go w/ the Xo1. if i had horns, i'd go w/ the EMM. beyond that, its personal preference.
ultimately, you cannot go wrong with either. and any personal preference i may have (which i don't at present) is not necessarily yours. suggest you hear both---they sound similar, but the differences b/w the two might be meaningful to you.