I hunted in Birmingham Ala. in that devil dirt red clay with veins of natural iron ore and tiny round particles of iron you could actually pick up with a magnet thrown in just for fun.
Nobody, and I mean nobody got much depth at all in the worst of that stuff.
My Vaquero, a friends E-Track, all the club guys Whites's...all had pretty much the same depth which was 3-4", maybe 5" on a good day in moist soil.
I got the Vaq and eventually a DD coil to combat this stuff to no avail, but it still found me plenty of great targets because most of them were 5" or less in depth, anyway.
Now here is the weird part.
I purchased an older 7" coil Compadre about a year after getting the Vaq because I am a jewelry hunter at heart.
I have never done any tests, or measured any finds, but I swear that the Compadre was actually getting me slightly deeper than my F2 or my Vaquero with clearer signals on targets at all depths.
Crazy, I know, the Vaq had way more power, manual ground balance and that DD coil, and yet it sure seemed that way to me when I hunted sites with the Compadre I had hunted previously with the Vaquero.
This does not make sense at all and I realize this, but maybe the different circuitry without the low noise high gain of the Vaq, or the true 180 degree ED of the Compadre might have had something to do with it.
Jewelry hunter, the Compadre... and that new 8" coil model should be considered.
For what you want to do I agree the Compadre or Silver should work very well.