The one feature I'd love to have is a feature that was
available years ago called "surface blanking"
This is where you could turn it on, and the blanker
would ignore all targets in the first 1 to 3 inch deep range.
I understand that it didn't work all that well back in the day, but
with today's technology I don't see why it could not be made to work.
Today depth meters are not accurate in inches, but they do a good job
of telling a shallow target from a deep one.
Sure you might miss a few good shallow oldies, but the trade off would be
almost all pull-tabs, bottle caps, zinc coins dropped in the last couple decades gone.
What features would you like to see?