I think dungeons are just fine - I actually feel like I get more EXP and drops in a dungeon than doing fates. I miss out on seals but that's it.

Yesterday was going through Aurum with friends and was getting about 1700 - 2200 EXP per each kill.

and when we're going through rooms with 5-12 enemies that's about 15k at LEAST a room - It doesn't seem bad to me at all.