If my understanding is correct, I think critical hit is an okay stat but no longer one of the best. You would need upwards of 2000+ for it to be useful for BLM (not 100% sure about this) a lot of BLMs I know, myself included are maxing direct hit/spell speed and just trying to balance out critical hit and determination to respectable levels. Though, this is what I have found from reading through the BLM mega-thread. Not sure if this is the answer your looking for.