Every new difficulty is just NewGame+. It's not that odd of a concept.
Well, if the game was designed so that NewGame+ was the *actual* game, I could see them taking steps to make the process as painless as possible. I wouldn't play through all of Chrono Trigger 3x to play the "real" Chrono Trigger, for example. Too much going around in all kinds of goofy paths for the storyline.
I guess the real question is how intrusive is the story? If it prevents you from progressing constantly so you can diddle off and rescue Deckard Cain instead get to Tombs level 4 or whatever, that would be pretty annoying to me on the 2nd or 3rd time through.
You have to do all that stuff over again, but honestly it's not that big of a deal? Especially that particular quest which is like... 2 seconds long.
It's not only about that particular quest. If there are many quests like it, it adds up to a bunch of stupid stuff that would sorta detract from the mindless diversion experience.
I'm still on the fence about getting this. I guess a lot of people seem to be going into as a mindless diversion thing, so I could go into it with that mindset and probably enjoy myself.
But if the storyline is too intrusive and keeps popping up, reminding you it's not a mindless diversion and it expects to be treated like a real game!!! then there is an issue. I'm just trying to click monsters, man, I don't care about Deckard Cain's daughter. I don't wanna leave this dungeon so I can go save her and get the key to the next floor, just give me the dang key here!