Low and slow for deep small or larger targets and faster if anything shallow. Different settings and machine dynamics. The two are at odds with each other.
Well all the above advice is true. However, you can definitely find gold with Equinox 900 as I did recently with Equinox 800. You learn to ignore the chirpy sounds from more likely iron related sources and anything that is more mellow longer lasting rise and fall of signal is suspect as a target...
A man has got to know his limitations. Heard that somewhere before. Happy days ahead Dave with a 6000. I stayed with 5000 partly for this reason. Can always put on a smaller coil later in the day.