I too have the MXT and it is my wife's detector as it is so easy to use and so much fun too. I have used it several times and it will go faster and you will get more new coins, but by the end of the day the Minelabs will have the older and better finds.
I feel if you are new to the Minelabs the Quattro or the XS II may be a lot to learn if the DFX was too much. The Sovereigns are more of a turn on a go detector with some good depth and ID to them, but like any detector this one has to be learned a little different than what you are using now. This learning curve is easy for some and steep for others, It took me a good 2-3 weeks to get comfortable with mine, my wife was doing good in one day and a freind I sold mine too when I got a new one that was using a GTA 1000 learned his on one afternoon.
The XS, the XS2, the XS2A, the Elite and the new GT are all great Sovereigns with the GT I feel is more sensitive, so if buying a new one then I feel the GT is the way to go, but the meter is extra. The Elite you get a 550 meter most have to rescale to read the 180 numbers as many of us feel for IDing this will make a big difference. The Elite dont have rechargeable battery either where as the GT does.
Now as far as meter that is a matter of prefference and I highly recomends one myself, but if you are a beach hunter you will be digging everything anyway so you dont need one. The Sovereign is a tone ID detector so as the conductivity changes the tone does too and some of these tones are real close in pitch and this is where the meter is real nice. With the 180 meter a nickle will read 144-145 while those pesky beaver tails off the older pulltabs will read 140-141, but sound close to one another. Now some of the newer pulltabs will read 170-171, but the new zinc pennies and the IH will read 176-177 while the copper silver and clad will be 179-180, but to some these 3 will all sound the same, but the meter can see the difference.
Some of the drawback to the Sovereign series is you have to go much slower and listen closer to the signals then your MXT as the Sovereign gives you the info and lets you decide to dig or not, other detector give you a beep and tell you it is one to dig. The Sovereign give you more info, so you have to go slower to hear and understand it. The Sovereign can not tell the difference in a penny, dime, quarter or half dollar, but to me it makes no difference as it is a target I will dig and see for myself what it is.
These are great detectors and the more you use it the better you will get with it, if you use it once a month it wont be too good, but if you use it 20 hours a week or more you will do great and pick up coins in areas many have given up on as being worked out.
Rick