I always use the default party cos I'm a nerd.
No actually it's because I hate mages - whenever I use them I die and I always prefer fighters with magic who can actually take a hit than some silly robed piece of bait trying to vain to defend themselves with stuff like clothes and shirts. :mog:
So default party it is for me. And I dig black belts - mine got me through the Ice Cave single handedly while the rest of my team's corpses steadily decomposed.