I use my GT Sovereign at the beach when I want to hunt the wet and dry sand at the same time because I don't have to mess with the settings.
If I was only going to hunt the dry and concentrate on finding jewelry items, I may go with X-70 with my 5 x 10 DD coil on it.
In parks I use the X-70 almost exclusively because I want to "Cherry Pick" what I dig. During the summer I hunt the beaches 98% of the time and the parks 2%. When the smaller coil comes out, it will probably replace the 5 x 10 coil at the park.
If I could only have one detector, it would be the GT with my Patriot meter and S-1 probe setup. I build my own straight rods so I have plenty of different rods and coils all set to go. I hip-mount my Sov control box always, so, it is just a matter of disconnecting the coil wire and grabbing a different rod and away I go!
Come on Minelab, hurry up with that smaller coil, I only have another good month of hunting the beach! I need that coil for the parks until we get (if we get) some storms to erode the beaches a bit.
I intend to keep both my GT & the X-70. I even have an older Sov XS as a backup to my GT. My relatives like using it too.