  The occurrence of a desert between neutron star (NS) and black hole (BH)
remnants is reviewed. The dependence of stellar remnants on the zero age main
sequence (ZAMS) progenitor mass for solar metallicity is taken from a recent
investigation and further effort is devoted to NS and BH remnants. In
particular, a density parameter is defined and related to NS mass and radius.
Spinning BHs in Kerr metrics are considered as infinitely thin, homogeneous,
rigidly rotating disks in Newtonian mechanics. Physical parameters for
nonrotating (TOV) and equatorial breakup (EQB) configurations are taken or
inferred from a recent investigation with regard to 4 NS and 3 quark star (QS)
physically motivated equation of state (EOS) kinds. A comparison is performed
with counterparts related to nonrotating and maximally rotating BHs. The
results are also considered in the light of empirical relations present in
literature. With regard to $J$-$M$ relation, EQB configurations are placed on a
sequence of similar slope in comparison to maximally rotating BHs, but shifted
downwards due to lower angular momentum by a factor of about 3.6. Under the
assumption heavy baryons are NS constituents and instantaneously undergo
quark-level reactions, the energy released (or adsorbed) is calculated using
results from a recent investigation. Even if NSs exclusively host heavy baryons
of the kind considered, the total amount cannot exceed about 10\% of the
binding energy, which inhibits supernova explosions as in supramassive white
dwarf (WD) remnants or implosions into BH. Alternative channels for submassive
($2<=M/m_\odot<=4$) BH formation are shortly discussed.
