Hello, One factor that has gotten very little attention is The Ground!
While Detector X may work very well in Ground Type Y and Horribly in Ground Type Z
Detector A may in fact be great in Ground Z and horrible in ground Y.
Could also be the detector setup as they are very configurable, so if yours is different, please share your setup so the detectorist having issues may be able to resolve them.
Let's use this to help each other, rather than point fingers, without at least trying to be constructive about it.
So far, it sounds like we are ALL on the same page, let's work towards keeping it that way.