That's not an upgrade, it's more like a bad headache that you had to pay for.
My cz-70 beats ALL Explorers (so does the cz-7) for depth in bad soil, and so does my Sovereign by about 1/2", and so does my Compass R&C by 1", and in mild soil the Tejon beats and Explorer like it's a red-headed stepchild, by a whole 2".
Why not get something really good, like an Infinium or an F-75? Someting that you can run fast or slow. An Infinium or F-75 goes really deep and doesn't cancel so much stuff when operating them too fast? Even though the Infinium likes iron a bit, it beats almost anything anywhere on black sand/ salt beaches for coins and jewelry depth. The F-75 beats the Explorer for depth too and certainly discriminates better when run fast.
The MXT would be a good nugget hunter or relic hunter but it's 950 coil LOVES hot rocks. The DFX does too, but with a different coil it would be a better bet over an Explorer too, unless of course you like to carry around a heavy dinosaur that you like to run real s-l-o-w-l-y.
I won't mention any names, but at White's main factory I was told that a Nautilus beats the MXT and the DFX for depth. They seem to think it is the deepest VLF made in America. That could be.