Direct Metal Mastering ( DMM ) LPs. What is this?

Some say they are harsh and shrill.  I've found them just fine.  I don't let it stop me from buying one and if it a recording I already have and like I may add a DMM to my collection for completeness.  Specifically, Dexter Gordon's One Flight Up and Jackie McLean's Let Freedom Ring are excellent and compare well to their non-DMM counterparts.

I think it's like a lot of things - no one factor is dispositive of the outcome. The Stockfish LPs are DMM and they are some of the best analog recordings I've ever heard.  So I wouldn't make a record purchase decision based on whether it was cut to lacquer or metal.  

The newer Rush remasters are also DMM. I am not a big fan, but did wear out some of their cassette tapes back in the 80's.  I was thinking of trying one of them, but the DMM is a slight deterrent. I suppose just asking Acoustic Sounds would have made sense.