Rick,
I am glad to hear you are seeing what the GT can do. I feel it has more power then the Elite I had, or maybe it just seems to be. I find the GT will be a real winner and think when more get them we will be seeing some great finds posted.
Now as you see the test with the preburried coins the Sovereign dont do well, but after they have been in the ground and all the air is gone they work much better. The things Sovereigns hate is air, speed and iron, so air test are not good, if you go too fast you will lose depth and it is rare that iron will show up as good. I have seen rusty bottle caps show up as nickles when the ground it very dry.
Now as far as a meter, for me I swear by them, but the tones is very important too. I like the meter for those close tones for IDing. Like you say the copper pennies, clad coins and silver will read 179-180 on our 180 meters if it has been calibrated to 180 on a new dime. My zinc pennies and IH read as 176-177, but the tones are so close to the 180 tone would be is one reason the meter is nice. Now the nickles if you use freq 2 which most find it the best freq to use a nickle will be 144-145, but in freq 1 they will be a little higher and read 146-147 I beleive. The ID meter on the Sovereign is very accurate and find it is the most accurate of any meter I have ever seen, but there is a limit too where it will be accurate. I find I can get a acrruate ID doing the Sovereign wiggle on coins 8-9 inches deep and after that i can hear the tones trying to climb along with the meter numbers, but they may never make the correct ones, or maybe just for a split second, but with expereince you will know it is a good target to dig. The targets should never read higher than normal, but may read lower trying to climb.A 180 signal may get to 170-177 if wiggled just right the same as a nickle may get to 140 but not lock on as it is so small of a signal being it is so deep. If it seems to lock on to any one number than that will be the ID of that target, if the tone is trying to climb and the meter is too, but can lock on is the ones that are too deep to accratly ID and you will know it is one to dig.
Many dont use a meter and go only on tones and I find that works good too as you will dig more and get more odd items too, but for me my main thing is coin hunting and I find the digital meter helps me a lot. Like any detector you can not go 100% by the meter, but with expereince and the tones you will know which ones are good. One of the nice gold rings I found I thank the SunRay meter as the tone sounded like a nickle, but the meter read where a beavertail off the old round pulltabs would read and I knew it sounded too good for a beaver tail is why I dug it.
The reason the Quattro was able to pick up the coins a bit better was it was using a 10.5 coil and I think if you would have had the 10 inch on your GT it would have too. I also know the Quattro has a slower recovery so it seems to lock on better from what I have used one. Myself I find I can ID much better with the GT than the Quattro even though the Quattro is one great detector. I feel some of this is the tones are better for me and my hearing.
As far as meters are conserned I like my SunRay DTI meters and the rescaled Minelab 180 which I feel do the best job and it is what Minelab has now made for the GT. SunRay no longer makes a meter for the Sovereigns, so those you have to pick up used. I never used a Patriot meter and would like to try one someday, but dont feel it will out perform a 180 meter.
As far as being unstable on the beach I dont know what that could be and if you change freq and didnt help i would hold the coil in the air while in auto and see if it got interference than. If it did then you know there is something around you that is doing it, but if you put the coil to the ground than it may be mineralization or black sand giving you the problem, but the MXT may have run stable, but I wonder if it would have got a signal on a good target. Nomaly the Sovereign is what everyone wants for beach hunting as they work good.
The MXT is my favorite Whites also and it is a great detector and will probably get more coins per hour as you can go faster, but when it come to quality and not quanity the Sovereign GT is the one to use and I am sure once you have used it a little longer and go back to many of those worked out site you will see they are not worked out, only deeper coins and coins close to iron or other coins the other detectors averages so they read as a trash item.
Good luck Rick and glad to hear you are seeing some of the power and ID the Sovereign has.
Rick
