My suggestions are:
>1. Yes, a larger coil can help in some areas for coins (assuming these are your fav. targets), depending on
the trash percentage. But because of a large coil's tendency to be masked to coins by trash because of it's
larger footprint, I'd not go larger than the Eclipse DD 8X14. The big 12" concentric is TOO big for coins due to
the masking effect. The elliptical 8X14 is having great success on coins because of it's deeper ability while
"cherry picking" in trashy areas for coins, being more effective than the stock 950 concentric. It's DD design
is also better in mineralized ground over the larger concentrics.
>2. The MXT is indeed extremely versatile for most uses. Just be sure to fine tune the THRESHOLD for
best audio as well as upping the GAIN as high as possible for best sensitivity.
>3. For target information, the MXT is almost overkill and has a tendency to spoil the user into depending
too much on it's great TID meter to the ignoring of the more intimate Audio responses. For this reason I'd
favor the coil and knob tweaking changes on the MXT before opting to change to a strictly audio detector
like the Tejon or Vaquero, although of those two I'd opt for the Vaquero, which has the same sensitivity
as the twin disc Tejon. Those two also have manual ground balance instead of the "automatic" GB of the
MXT. In some areas a manual GB can enhance audio response on deeper targets over the auto. type.
>That's about it IMO. I really believe your MXT can find the deeper coins you seek by doing the above,
instead of the more radical change to another detector. For now, anyway.
Best of luck in finding those productive sites!
..W