I had an F70. Did not like it real well as the numbers were jumpier than AT Pro & F70 gave off loud noises on what I think were hot rocks.
The AT Pro has the most accurate ID at depth I've seen. Got a dime down 7" that IDed as dime (80-85 range) on every sweep. Ground was hard & dry. Depth read 8". This was using STD mode, coins program, sens 7 of 8, iron completely rejected (40). Sure I may have missed gold, but dug almost no trash & it was usually something small & round (like a button) when I got trash. Otherwise totally silent. I did not get good depth until I set the ground balance more or less correctly. Other than that, STD mode requires very little learning. I will likely try the Pro mode someday, but prefer easy & relaxing STD for sites that aren't real trashy. Best wishes, George (MN)