What do you mean by midrange fullness?
The HE-4 has somewhat recessed mid-range compared to the HE-5xx. Full means more meat/flesh on the bones. It is more like a TH-600 in its presentation: U-shaped and fun but vocals can sound distant.
The HE-560 seems to lessen the fun factor in favor of a more neutral presentation and, by all indications, better technicalities.