They say there is no build diversity
But with about 25 hours in this expansion, a case can be made that it does have a level of build diversity that have manifested with the latest update. This is the first time I’m planning on building a healer once I get my DPS build straight for flexibility. In the past I could out DPS all PVE content in the game and carry a team on heroic. More DPS was the answer, always. Now with the added health and armor of the NPCs at the higher levels( heroic and up), a healer or a tank might do more for the team than just another gun..this is a great first step in returning thought to the series, rather than a 4 man coop NPC firing squad simulator with success never in doubt.
As far as the single player aspect, after playing the story solo I grind coop most of the time. But Ive been in 4 man challenge coops with seeker builds that maimed NPCs so bad, they were walking dead. Easily cleaned up. I could only imagine what they do when the game is scaled for solo.