I believe all the rebranded versions of the HM5 (FA-003) are basically the same. Some differ in accessories though.
XB700 has LOTS of bass. HM5 is aiming for a more neutral sound, and I'd say is definitely more versatile with various genres of music. XB700 is quite gigantic, but very comfortable. I'd say comfort is quite close, but the XB700 probably gets the edge for me. While the XB700 is focused on the bass, I've found it can be EQ'ed into something real nice providing you have an EQ to work with. Was never really a fan of the HM5's soundstage presentation, as it sounded like it was echoing.