I like the MI6, and only use it with the ORX. I would use it with the other detectors, but find it a pain to re-pair it. as for sensitive I crank it up to max. I am usually able to pop a target out with a screwdriver, something I am rarly able to do with my Garrett, as the Garrett is an area locator, it puts in the ball park as to where the target is, maybe other people have had better luck than I have, but most of my holes grow to a 10 inch diameter using the Garrett.
as far as detecting small gold (Nuggets) it will not, nor will the Garrett, neither one of them will even detect the Screw in my thumb, the ORX will, I also have the fisher f-pulse, it also will not detect small gold or the screw.Larger gold that tips a scale yes they probably all will sound off.