Congrats on that silver. Have you slowed down your swing since you started to swing the E-Trac? I suspect that may be why you pulled the 6" silver. You may have thought you had a false signal and skipped it using the F5. I am not versed in the Minelab 705 you had, but I believe you had an 8" concentric on it, which means you may have not overlapped your coil sweeps enough to get max depth at on that coin. I am glad you are pleased with the new machine. The E Trac is on my top 5 list of Detectors. (the poor man's CTX)
The sounds a Minelab makes give a lot more info especially in multi tone mode. You can tell how deep, if there is iron close to the target, if it is odd shaped, etc.