A real letdown was the kind of attention Mr. Metcalfe gave to the difference signal - does he know anything at all about psychoacoustics!?
I've seen the phase reversal trick used on a few occasions now to show "how much is missing with mp3". What's interesting is that, especially when presented with higher bitrates, they can't actually make the case that people can hear the difference when you play them side by side, so instead they have to present you with "the differences" so that you'll understand how truly horrid mp3 encoding is.
The difference signal has no meaning at all regarding lossy encoding. How is MP3 "horrid" if it cannot be ABXed/differentiated with certainty? If a lossy codec is transparent to most listeners it achieved its purpose.
In my opinion MP3 is horrid because of the ID3 tagging disaster and non-gapless design, the audio quality is certainly not a major issue, as has been shown in community listening tests. I, myself, have a very hard time ABXing LAME -V4.
I should've been more clear - I also would've put quotes around "horrid" in my original post.