With many types of music, it will be hard to diferentiate 160kps and 192kps files, but this is not always the case. The more complex and demanding the music is, the more resolution it needs. And I can't tell the difference between 48kps and 32kps, but I know they are both less than perfect!

Indeed, there are some parts of some songs that may require 320kps (especially in the car where our sound systems are better than computer speakers with noisey soundcards).

I think the best solution would be to use a variable bit rate scheme where the song is encoded at 160kps where the music isn't that complex and at upto 320kps when it can pay off. (The program analyses the music to determine when to use a higher resolution.)

But, on a home machine, where disk space is so cheap, 320kps might be good for archiving.