We all know the MXT is not a beach machine and will have the problems that a single VLF detector has at a salt beach. With that said, a lot has to do with which beach you will be hunting on.
In any case dry sand use is not a problem, but it does get a tad noisy in the wet sand and surf. A sweep pattern where the coil is not alternating
between wet and dry sand works best. I would ground balance on the dry sand and then lock the GB and search. When it was time to move to the wet sand, I would ground balance it again and then lock it once more. When in Texas I ran in Relic mode and used the 6x10 coil. On those beaches it ran fine.
I haven't hunted the Florida so this post by Da, Fox might help.
Obvious warning: The MXT is not water proof, so be careful of the salt water spray.
When hunting along the surf line, always keep the coil lower than the control box
to prevent salt water from running on the inside of the rod into the LCD pod or control box.
Yes .... I took the 10"DD over to SunSplash Park (Daytona Beach). Like ANY circular DD coil, it is sensitive to being touched to wet sand. Doing so will result in "falsing". This is indigenous to the circular DD design, and NOT specifically to the new 10"DD.
Operating the coil in dry sand resulted in about 12" depth on a quarter. To keep the coil "quiet" in wet sand, I held it about 1" off the surface and got good results, but after a while you get tired ....
If you want to use a DD coil on the beach, the 6X10"DD is the better choice. However, if you want good depth and seamless operation from dry / wet / dry transitions, the 950 concentric does a great job. That's what we use on the beach. It will just about match the depth of the 10"DD owning to the fact that our sand / soil is very low in mineralization.
Rob