Also tried it and got to lv4 on opening night. Came in the next night only to find I'm out-leveled by groups looking for 6+ people. Now I don't want to touch it ever again. If i had to describe it to someone who didn't grind diadem in HW days it would be like an area with a nice shiny weapon hanging from the ceiling but there's nothing to do except spending countless hours killing mobs and using the bodies to make a tower way up to the shiny weapon. It wouldn't be too bad fates never spawn unless are grinding select mobs, and the difficulty is fake to discourage equipping multiple jobs. The elemental revolver is cute but its also broken (can't control rotation direction with ps4 pad on pc).

If i were to suggest improving, I would flat out increase xp and crystal drop rate by 50%, make the fates forced spawn if the conditionals aren't met by say 4 or 5 hours real time, and add exploration activity to reduce the reliance on mindless combat activity to progress.