HDMI Audio Quality vs Optical/Digital/Analogue

Have any of you done experiments comparing audio qualit, via HDMI to alternatives - optical, digital, or analogue? I'm wondering if HDMI audio is necessarily equal or better, or, does it depend on other factors (or inferior?).
If your preamp or receiver do the new codecs (DTS HD, Dolby TrueHD) and you have HD DVD or Blu-ray it is a huge step up, akin to MP3 vs. CD.
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Also, for music, if you get a receiver/processor with HDMI 1.3, AND a SACD/DVD-Audio player with HDMI 1.2 that can send DSD and DVD-Audio via HDMI, the sound quality is fabulous. You can get an Oppo 980 for $169. I have it, and SACD DSD and DVD-Audio go directly to the receiver. This also allows you to do away with all kinds of interconnects.
Analogue is good.
Coax Digital is better.
Optical is much much better.
HDMI is best.
HDMI 1.3 with DTS HD or Dolby Tru HD is fabulous.
so far
In response to Mtrot: Correct me if I'm wrong, But I was told that Coax-Digital has a higher bandwidth than Optical. I use Coax for my home theatre 5 channel listening and it does sound better than Optical..just a listening fact....

Coax digital has wider bandwidth than the original TOSlink interfaces would permit but TOSlink has been improved to its equal today.