I agree a good sound man is worth his weight in gold, but I'm afraid most of the ones I've encountered in the last 10 years or so don't know what they're doing. Whether it's a function of them being deaf from too many hours of too-loud music or they're catering to audience expectations, most are starting with their main gains too high. And from there it's impossible to get sound with any subtlety.
I had never heard of laws limiting the dBs before, but I wish somebody would start it around here. I can't even go to a movie any more because the volume levels are so high it's painful and the dialogue becomes just muddy noise to me. Same thing with most concerts — even some folk concerts I've gone to lately.
enough of that rant.