Good afternoon Tony!
I couldn't agree more. DCC Sound in large locos working large and fast trains as demonstrated on your layout is simply redundant. However, since my layout is a mear 12x1ft 1960s MPD based on Doncaster, I feel sound may have the potential to be better utilised, since as you'd expect, there'll be lots of low speed chuffs, puffs, whistles etc.
I'm looking forward to seeing the video Tom has filmed on LB.
Many thanks,
Dylan.