I used to do sound mixing many years ago, and the technology has improved in leaps and bounds, but the sound doesn't seem to be getting any better. I often see someone playing away on an instrument and there isn't a trace of it in the mix. I do question whether many operators know what the different instruments sound like?

Then there is the question of volume. My suspicion is that operators have monitored at such high sound levels for so long they have mid-range deafness. Many's the gig I've been to where the mix sounds better from the foyer than in the hall. I know see people at festivals wearing industrial ear protectors!