See Post #1, dmaz.
As you can see from my own experiences opening 200 packs, I got 9 Masterworks in the first 100, but only 1 Masterworks in the second 100. Not consistent at all, at least for me.
I've been trying to get the Masterworks Aragorn and Madril from the Hunters set. At this point I think I've got multiples of almost every Masterworks from that set... but still no Aragorn or Madril. Very annoying! The only other Masterworks I don't have from Hunters, is the Christmas Gandalf.