Quick somewhat of a comparison, same settings, same targets in test garden (aged a couple years). Really not much difference on dimes, other than the 15” makes it hard to miss anything. The 14” nickel is where the 15” shows very slightly more reach, not much, but a bit more. This was just my quick testing for me, but figured I’d record and post, cuz there’s not many videos comparing same targets that have been buried awhile. Likely that the 15 would show more reach the larger the target is, not certain.
*Settings: athc for dimes, atlc for nickels, really not much diff. 26 sens (is the magic # for my ground), 4 recovery, 1 stabilizer, medium audio, gb 13-15, all metal, all tones 1 region