Like Okie said, the ability to utilize your machine's depth capabilities will depend on settings, as well as soil conditions.
I don't hunt in all metal, though I will occasionally do so at large open fields and meadows. I do get plenty of depth with the E-Trac while using a discrimination pattern. Depth, however, is not what I am primarily interested in. I find most coins will be within the depth capabilities of most detectors. I like to work trashy parks, areas others tend to give up on. The E-Trac excels at such areas. That's where you can pull some really good stuff. For those who are not used to using variable tones, hunting in such areas may drive them batty.
Back to depth though, when I used to work the DFX at parks, listening for the very faint signals required concentration and careful hearing. The E-Trac has made that much easier, raising the listening for 'faint' signals' to a different level. If I hear a 'crackle' I will investigate it, sweeping over the target from various angles, noting signal consistency, Fe and Co variance, if it pinpoints where the discriminator is indicating the target should be, listening for tone variance and quality. Experience here can be very important.
Talking about it now makes me want to go detecting. :grin: