Is there really any reason to play NewGame+ aside from wanting to replay the game regardless? More unique blades is whatever, and starting with a ton of stuff already would just make the game uber easy.
Well, the new blades are the main draw, but if you don't want to collect them all, then there's really not much of a point to new game+. You keep all of your blades with their unlocked perks and equipped weapons, so the game is easy even if you reset your character levels to 1.
The very few quests that have slightly different outcomes aren't worth it to see them either.