I have a .5 ( 1/2) gram gold nugget and decided to test my 3 detectors. All 3 were set with DISC settings at the minimum and were tested in the same exact room and spot in the house.

The Whites M6 ( 14khz)with the stock coil set just a little past the SENS presets without chattering,and no ground balancing, saw it at 1/2 inch---Loud and clear.

The Garrett AT Pro in Pro Mode -Zero more sensitive to EMI inside the house, and setting the SENS to 2 bars instead of 6 bars,so it wouldn't chatter, and on auto ground balance, saw it at 1/2 inch-----Loud and clear.

My IDX ( 6.59khz) with 9.5 inch coil, saw it at 1/2 inch , only after setting the SENS at almost the maximum setting without chattering----Loud and clear.

The M6 and AT Pro are close to the same frequency ( in the 14-16 khz range) but in my honest opinion, outside with a good ground balance and maximum adjustment setting the AT Pro would be able to detect even a slightly smaller nugget at a slight more depth than the M6 could.