Upsampling works within reason. (heard a non-amarok setup a few years back.)

I've seen (and heard) an upsampling setup (I think it was both hardware & software) first with the regular source file, then with the upsampled file.

On decent speakers you can totally hear the difference. It sounds "fuller". (I made my friend do a "double blind" study utilizing his gf arranging songs randomly with and without upsampling without telling me. I can totally hear the difference. I called out which songs were upsampled and which were not correctly)

I'm kind of wondering if that would make my 128k mp3 files sound better.