i tested it fully using file encoding mode in nero. the output quality is identical to the mp3pro quality. if you do it to mp3, of course, you need to use a high bit rate. i haven't gone through different bitrates yet i just used 192 for normal mp3.
its easy to test, just turn of the encoder options in winamp and listen to your new wave/mp3 and then to mp3pro version. the mp3pro versions sounds dull and horrendous and the wave/mp3 sounds bright like it the mp3pro turned on!