Originally Posted by HungryHunter

after xome experimentation

Lvl 11 is my best one since I can use 30 stuff x2 w/o needing to go to 80

beyond lvl 11, I have to use 80

HH, if you're farming the equipment upgrades (which is the only reason to be doing any bosses past L4), then you're better off spending the 80 on L12 since the L12-14 bosses give two upgrades whereas the L11 only gives one.