its a ggod training spot, up to level 48 i think, after that it takes to long to level and the pay-off isnt good enough (only 2 SP per level and the levels dont come fast enough) --- Playstation Network Online ID : Lloyd, PS3 120GB with YDL (originally 20gb) owner of DS, PS3, Crisis Core PSP #05215 w/custom firmware + 8gb memorystick
You are far better off at that level spreading out your levels over classes and picking up permanent bonuses. Stats and skills over a large spread of classes > 1 class at high levels.
Metal brothers (the slimes stacked up that you mentioned) give around 3-4 k xp depending on party levels and such. I found after level 25-30 it slows down, and they run away often. The monsters in that cave also dont give that great of xp outside of metal brothers.
Make a fighter (people are calling them monks here) get as much of his str/speed/whatever from his class skill as you want, then dump into bare hands. --> battlemaster. Get all the stat boosts you want, dump into bare hands. ---> Theif get the speed/skill/skills you want from his theif line, ---> dump bare hands. Doing this you can easily get tons of stats, and 100 bare hands skill. After that, you have an OBSCENELY good fighter with bokuretsuken that kills just about anything if its solo(at least until the monster cave) and gets 4 swings on metal monsters (each one can crit, and it only takes 1. For extra damage/power, you can switch to paladin for defense/hp, then Soldier for str/defense, etc.etc....
Do the same getting magic power for mages, healing power for clerics, etc etc. Be aware that Ive found a number of errors on the skill faq on this site, so I hope you can read japanese in order to get the boosts/skills you want.
After you do this for most all your characters, you can move on with the story and basically ROFLstomp your way to the monster cave, which opens Haguremetaru for you to kill, which is around 3X as much xp as metal brothers.