Mastering quality is the foremost important thing to sound quality. Then I think the chain goes 128 kbps < 256kbps <= 320kbps < lossless FLAC/WAV/ALAC I can't tell the difference between 16-bit FLAC to 24-bit FLAC. I only have one Eagles album in 24-bit / 192 khz and I don't have a 16-bit version of that file to compare.. but every time I listen to those tracks they never ever come across as sounding anything like a 256kbps mp3 and have much better SQ. 320kbps and FLAC can be impossible to tell the difference with SOME tracks.. I have heard the difference on a specific album I own a 320kbps and FLAC version of and can prove it blindly. I wouldn't be afraid to back up my claims either if there is another meet coming up or if people near me locally would want me to put my money where my mouth is.