I can attest to Danny's methods for sure and when he says this stuff, he's not preaching or throwing out technical stuff for the purpose of impressing anybody either. At the start of working with him on this record I thought I had the mixes pretty good.... with his guidance each of the 10 songs on the record sounded a thousand times better even before he mastered them. getting the sub lows and rumble out of the way at the mixing/track level was huge.
Everyone on here has always given me props on my guitar sounds which stands to reason and Danny liked them too... however everything else in my mixing was out of whack. Bass was too low (tone/frequency wise), kick was too low, toms....too low, vocals often needed more presence & then a De-esser (do ya see the pattern here?).
The differences between what I had at the start and the "final mixes" are like the differences between a rough mix and a good quality demo, then he mastered them and they just stomp and you can crank em til your ears bleed and your head friggen explodes but the speakers still don't distort! It's nuckin' futs.
At the end of the day I would try to learn his techniques but there is soo much left I still need to tackle on the recording side that well.... for years to come I will leave the mastering up to him so I can concentrate on the rest of it. Mastering is a whole other art that is appropriately named and is best performed by a "Master" of that art.