I just leveled BRD and BLM to 50 the last couple of weeks. It was pretty painless but somewhat repetitive. Leve and Fate spam while in dungeon queue. The new hest and challenge log bonuses are a big boost as well. Don't queue for the daily roulette more than once per day - queue directly for the highest level dungeon after you get your bonus run, and if I have just reached the first level that I can get into a new dungeon before I do my daily - I will skip the roulette for that one level to get more bonus exp.