I will admit that I am far from the high-level content. But from what I have been hearing the spells themselves are a bit impotent. If that is the case they should also adjust the spells to be more powerful and more worth the cost of MP. I have always envisioned magic users as powerhouses that are leashed by their dependence on MP. Also, abilities that would allow for MP regeneration in battle (Refresh, Ballad, etc...) could help mend the poverty of MP in the endgame environments.