Rite, first off i`m not a expert like some of u seem to be, nor do i own an Empeg, although i know what sounds good, and I am very very fussy.
However, after reading through this thread (very intersting btw :) I can see one huge problem.
You all seem to be comparing mp3`s made in Audiocatalyst, which without a DOUBT, is the worst sounding encoder u can get.
Its pitiful, it crops more high frequencies that the others, I`m not surprised people are finding treble lacking.

Usin an encoder such as Lame (http://www.sulaco.org/mp3/), I really can barely tell the difference between mp3 and wav (usin HQ VBR mode 1, roughly a 180kbps file)
Check out this page for proper graphs and such, highlighting Xings (ACAT`s) below par performace.
http://www.r3mix.net/

Says it all really, even if u dont belive graphs, or others results, you must be deaf if u cant hear the difference between ACAT and Lame or any Fraunhofer encoder.
I`d recommend Fraunhofer (Radium release, or Opticom Mp3 Producer Pro)@ 192kbs, or Lame set to VBR mode 1.
Give it a go, you have nothing to lose and i think you`ll be pleasantly surprised.