I use around 400 mf on my blizzard sorc pindle bot. I run MMbot. 400 seems like plenty mf. I have been running for a couple months and everything is fine. I dont increase mf because I max damage for faster run times. In two months of runs with this mf there is nothing I don't find. (Except Tyreals and Arachnids) I have picked 6 sojs in this time as well. (US EAST LADDER)