Are the two new jobs worth it?

I'm currently fighting the different districts in New Lumos and they're pretty tricky, I unlocked the Vampire and Self job a bit after post game and I'm wondering if switching to those classes are worth it? It seems like it'd be difficult to level them and buy them weapons and clothes to be actually strong enough to do something, but I don't know much about the two classes and would prefer minimal spoilers about their skills and such, my team is basically half magic attacked and half physical attackers if that matters.