from the preview Dark Zone = best loot (Off-Topic)

by Durandal, Friday, January 29, 2016, 15:41 (3224 days ago) @ Xenos

Difference is though you never have to go into the Dark Zone, it's only if you want to have some PvP fun.

From the preview videos all the high end loot is in the Dark Zone, so you have to go in if you want to get high end gear. Similar to Challenge Mode Raids and ToO being the only option for 320 loot.