And their IS a difference in AXY/MXY's and FatBoys: The short version:
MXY's are like good studio monitors: Perfect presentation, but a flat response, a bit cool in their presentation.
FatBoys are like VERY good (think something out of 'The Absolute Sound' or 'Sterophile') stereo speakers: Very precise presentation, but a little more 'seasoning' marinated into them vs. MXY's.
Not a night and day difference, but you will hear it.
J o e y