I'm only rolling about 169% MF. My skills are from a pre-patch sorc. I'm using a lvl 33 fireball, 33 meteor, 33 fire mastery, and lvl 18 firebolt.
My strategy is tele to Meph or Andy real quick, if it's Meph, I hit him with a charge of lower resist from a Kris in weapon switch, and cut him down with fireballs at 120% FCR. Works well, but I can stack more MF on her. I'm just too lazy to level her further.