I just replied to your question on another forum but since you asked here ,this is my impression of the M6.
When thinking about which detector would be my next "buy" "sell" victim i was a bit leary choosing an M6 with the dial discrimination but since using it and learning to focus on the 7 tone Id i wouldn't use notch much anyway because it separates and changes tones quickly even in heavy trash. Have found some good stuff listening to everything and digging the slightest tone differential which could be missed with notched segments.
Very rarely have to look at meter as the tones are good enough but like the depth readout.
As far as rating the M6 for parks, schools,fresh water beaches !! I now look for trashy sites with the M6 armed with a small coil and couldn't be happier

HH Bill
