If its in the budget I recommend going for the FXZ200, I remember it having better details than its sibling and noticeably better overall. I only spent less than 5 minutes with both of them during the big headphone show here in October but I remember enjoying the warm sound of the FXZ200 quite a bit.
The reason why the FXZ200 sounds noticeably better is because of the housing material and cabling, it is made with a more rigid metal and the cables on the FXZ200 are made of oxygen free Silver which I felt brought out greater resolution.
EDIT: Correction it seems that the cables are made of oxygen free copper that are silver plated.
Wow! Thanks for the tip Donnyhifi. Unfortunately I ordered the FXZ100 this morning before reading this. I was going to get both anyway. Maybe I might go ahead and order the FXZ200 too and be done with it. So you didn't like the FXZ100 at all? If not, why?