The MXT will work excellent for coins too, I have the Minelab Sovereign and Explorer too which will do a bit better then the MXT for coins, but the MXT will be close. The Minelab seem to go deeper and will get get some the MXT cant see too, but when we have done a side by side comparison on accual target it is close as the MXT can see most of them. The big thing with the MXT is the learning curve is not bad and so much easier to use and understand than the Explorer, but once you know the Explorer it can do great things as we see looking at the fourms by those that know it well.
Being you have the MXT I would use it for coin hunting and see what you can do. I run mine in the relic mode as i like the 2 tones and run my disc to the first mark and sensitivity without going into the + and when in a cleaner area I will run my sensitivity in the + area.
Up here in ND I have dug quaters at 9 inches with no problem, a brass key at 12 with the 6X10 coil and in heavy trash the little mini shooter 4X6 coil has got me many of coins at 6-7 inches.
Rick