Best PvE is still in the DZ.
For me and my friends the problem with the DZ from day one was that the best PvE in the game was locked behind a bizarre PvP mini-game. In terms of level design and overall PvE game mechanics playing solo or with just one group in an otherwise empty dark zone has been by far the best experiences I've had in The Division, it's only happened to me a handful of times... it seems lobbies sometimes die after 2-3 hours, particularly late during off hours. I would play in a PvE dark zone limited to one group only even if there were fewer drops, no xp, and no DZ funds. Because it's an amazing game, maybe one of the best I've ever played. This would not negatively effect any other players experience. Fighting bosses and extracting loot is super fun, I can't shake the feeling that The Division would be an overwhelming success if everyone could experience the dz without someone else being in their game. It's like Tom Clancy wrote an amazing novel, but the last chapter was written by an inexperienced game designer and the result was a train wreck. That being said a PvP/PvE DZ should always be the primary focus. I've also had alot of fun in PvP, making PvP builds and testing them is great... but it's for a few laughs now and then. For players like me, who PvP primarily in dedicated experiences like battlefield, overwatch, or world of tanks, please let us play your amazing PvE game in the DZ, and show others it's one of the best PvE games ever made.