Fes is pretty much the regular version with a few upgrades such as an epilogue story. PSP has some downgrades and some upgrades from Fes. PSP lets you control all of your party members and lets you play as a female character which changes the story slightly. But the PSP version has no 3dworld and instead you move around with a cursor except for Tartarus which is still 3d. Because of this, I recommend that you play FES first. Then if you want to play a 2nd time then play portable as the female character. EDIT: Also forgot to mention that portable has no cutscenes as well.