Well, I also heard theres a bug with 199% MF, so what I'm going to do is test this. I'm going to take off my Tals Belt, and Armor, lowering my MF to 181 or so %. I'll MF awhile and see if I get better drops on average then 389% with Tals Stuff on. Then I'll try the 199% thing, because I'm also urious about that.
EDIT: I siwtched my tals belt with arachnid's mesh and my tals armor with Vipermagi, lowering my total MF to 181%. At first, I got rares, some sets, etc. Then I started getting ALOT of uniques. Left and right, they were low level, but in time they got better. unique Blade Barrier, Guilded Shield, Matriarchial Bow, and a unique jewel and a unique Grand Charm were among some of the items I MFed today under that specific chart above. I have to say I'm quite please, however I will try 199% MF tomorrow to see if anything changes. ^^