You are right Gramps the MX Sport is very sensitive especially if compared to the AT Pro (of which I have one) and for that matter many other detectors.
I to had questions about its ability as a useful multi-purpose detector, it was so different to other detectors I've used in the past 35 years that I could see it wind up on eBay unused.
However I consulted the User's Guide which confirmed the MX Sport was indeed different in the modes I had question marked; back to testing the obtained info ..... the MX Sport is no longer considered an eBay item, in fact it could just turn out to be an exceptional multi-purpose detector.
A few more tests will be conducted, one of which will be between the 10"DD and the 9.5" Concentric on a wet ocean beach and in the water.
It is said the Concentric coil is better for wet beach and salt water work than the 10"DD, better not dispute that before one have the facts by doing it oneself, or if someone else can post a video of said test.
Another test will be on our gold fields to see if the MX Sport have enough ground balance ability to eliminate the mineralised ground effect in these areas.
So there is a few tests to look forward to.
Bottom line: The MX Sport needs a good deal of understanding.