  It has been well established by today that the concept of holographic dark
energy (HDE) does entail a serious candidate for the dark energy of the
universe. Here we deal with models where the holographic bound for dark energy
is not saturated for a large portion of the history of the universe. This is
particularly compelling when the IR cutoff is set by the Hubble scale, since
otherwise a transition from a decelerated to an accelerated era cannot be
obtained for a spatially flat universe. We demonstrate by three generic but
disparate dynamical models, two of them containing a variable Newton constant,
that transition between the two eras is always obtained for the IR cutoff in
the form of the Hubble scale and the nonsaturated HDE. We also give arguments
of why such a choice for the dark energy is more consistent and favored over
the widely accepted saturated form.
