But the wing produces lift much more efficiently than than the tail so it is about a wash on overall efficiency. Sailplanes, which are very sensitive to how efficient the lift process is , have about the same minimum sink rate over their range of useful cg positions. Aft cg produces increased response to EL inputs but at the loss of pitch stability.
Nose heavy sailplanes have a strong tendency to pitch up when sped up by making a shallow dive - same idea as increasing speed by advancing the throttle.