What is the potential for hi-definition audio on blu-ray compared to SACD? I'm still growing my SACD collection and have picky ears, but I was 'subjectively' impressed with the audio on the David Gilmour "Live at the Royal Albert Hall" blu-ray. The specs listed were 'only' PCM stereo 48kHz/24bit or Dolby TrueHD surround 48kHz/24bit. Quality audio on blu-ray is clearly not standard (I was far less impressed with the Elton John anniversary concert blu-ray). But the Gilmour disk intrigued me about the potential for audio on blu-ray. Anyone knowledgeable on the best that blu-ray could do with audio? Any music / concert blu-ray recommendations?