DSM is so much broader than the earlier system that it makes ground balancing less demanding. While this provides greater tolerance, it also requires an extra bit of 'tweaking' to get the best ground balance possible. Mode 11 is a setting for beach detecting which has no need for ground balancing and gives amazing depth on sand. This just illustrates how the least amount of GB used the better the penetration. That is why is is necessary to adjust GB to the lowest setting possible before the coil makes noise going up and down. Having a tiny sample target is helpful in achieving the ideal GB.
For whatever reason, the X coils run noticeably smoother than others, but whether this enables even better GB is something of which I am unsure, although I would guess that it is a distinct possibility. What I do know is that X coils enable QED to run on higher gain and lower mode than is achievable with other coils.