The entire point of the level system, player wise, was for you to take advantage of the --- Bonus abilities some of the GFs have. On the monster side though, the levels also determine what they have dropable/mugable. For instance, you can only mug a power generator for Ouistis by stealing it from a lvl 30 or higher Blitz and even then, its a low chance.
To be honest, the game gives you a lot of AP for abilities. The only reason you would need to grind is for a particular ability. Personally, I sit in the dream forest until I have Diablos' Mug and from then on just play the game.
To be honest, the game gives you a lot of AP for abilities. The only reason you would need to grind is for a particular ability. Personally, I sit in the dream forest until I have Diablos' Mug and from then on just play the game.