Welcome to the Alien. You have been assimilated!
It is deep. Goes deeper than my Gold Bug, which is pretty sensitive. The Gold Bug's stock coil is smaller than the T2's, which probably explains some or most of the difference.
Some air tests:
Penny(zinc-copper) GB 7.5-8" / T2 11-12"
Nickel GB 9" / T2 13"
Dime GB 7" / T2 11"
Quarter GB 8.25" / T2 12+"
Half Dollar GB 9" / T2 13-14"
Plus, again just air tests, it reads a smaller gold flake than the Gold Bug will.
I haven't taken it to the schoolyard to coinshoot yet, but set below 40 a bit might be a good starting point for disc. Myself, I like to start low, maybe even at zero, and work up as the level of trash dictates.
Disc level follows ID exactly. If you hit a lot of trash at 29, for example, a disc of 29 will eliminate all "29" ID's and lower.
I have not really had a chance to investigate the tone modes other than fooling around making beeps.
Let us know what you think of it when it arrives!
-Ed