I agree, I’d know the difference between my own two amps (Ashdown ABM600 & RM500) if I were on a very large stage, but would I be able to tell if I walked into a venue if a bassist was using Class D or A/B without looking at the set up, well I very much doubt it.
If anything I think this thread is a bit unfair on Class D amps, they’re not full valve, they’re not A/B, so maybe we should look at them for what they actually are, rather than what they aren’t. I know my gigging life has been made a lot easier thanks to Class D amps, although I do prefer to use my A/B amp if possible.