Most eTrac and CTX users oldie not get all there is to get out of the machines. They stay inside the shell of the 12 Fe line and use that to cherry pick coins. Basically the jest of it is 12-12 to 12-14 is probably a nickel. 12-42 to 12-44 is probably a dime. 12-47-1248 is probably a quarter. It would be just as easy to say the 12 Fe number is a moot point, and could just as easy say 12 to 14 is a nickel, 42 to 44 is a dime, and 47 to 48 is a quarter. The majority of diggers never get outside of that 12 line box and are quite confident in their cherry picking ability...they get the easy isolated, shallow to mid depth coins and are happy.
I would be perfectly content with Co numbers only. Matter of fact, anybody that has used the CTX will agree that the display sucks in sunlight. You can't see the meter at all in most cases, and have to rely on audio/tone. In water, it is the same way. The only time I can enjoy the benefit of the display on the CTX was at the beach at night. During the day with or without sunglasses....forget it. Simple and basic menu adjustments were a PIA unless you found a spot where you could block the sun and make it somewhat dark.