Only played the GBC version of this so I'll be rating based on that.
8/10
There's too much grinding, you're expected to find some things in the middle of nowhere without adequate hints (Final Key!), and the class/personality customization isn't as accessible or explained as much it should be. I really love this game though. Got all the way to Divinegon on a solo-Hero game once.
Also the monster animations were pretty amazing for a GBC game and put most of the SNES RPG library to shame.