Honestly to me the only content I feel really lacks any fun for a sync is anything sub 60.

From 60 most jobs have a pretty big kit and can let you get your bearings down for getting the core of your rotation. Like a BLM at sub 60 not having Fire IV just feels so wrong since that's your main mp user.

GNB is one where at 60 I think the kit offers a good amount and the rest to 80 are buffs or help build on it.