Catching sardines will lead you to catching salmon.
If you were covering ground, no signals and no gold, you just keep walking. If you find a small bit, then another, you then know there is gold where you are, you slow down and start detecting properly. The 6K will be a patch finder for sure.
It will detect good pieces at depth.
I saw a video that a tester made. He found 11 very small bits, 7!which the zed did not see. They put some time in, the zed got a good signal, and the 6K also got it. With the 11 mono v the 15 zed coil. It was a 7 gram bit. The zed got a better response. The point is, if the 6 K didnt get the 1st small bit, then none of the other bits would have been recovered. This video I saw was the 1st and only time this tester used it, so he was using it at a very basic level.