  Whether analytic exact vacuum(electrovacuum) solutions of the
Einstein(Einstein-Maxwell) field equations can accurately describe or not the
exterior spacetime of compact stars remains still an interesting open question
in Relativistic Astrophysics. As an attempt to establish their level of
accuracy, the radii of the Innermost Stable Circular Orbits (ISCOs) of test
particles given by analytic exterior spacetime geometries have been compared
with the ones given by numerical solutions for neutron stars (NSs) obeying a
realistic equation of state (EoS). It has been so shown that the six-parametric
solution of Pach\'on, Rueda, and Sanabria (2006) (hereafter PRS) is more
accurate to describe the NS ISCO radii than other analytic models. We propose
here an additional test of accuracy for analytic exterior geometries based on
the comparison of orbital frequencies of neutral test particles. We compute the
Keplerian, frame-dragging, as well as the precession and oscillation
frequencies of the radial and vertical motions of neutral test particles for
the Kerr and PRS geometries; then we compare them with the numerical values
obtained by Morsink and Stella (1999) for realistic NSs. We identify the role
of high-order multipole moments such as the mass quadrupole and current
octupole in the determination of the orbital frequencies especially in the
rapid rotation regime. The results of this work are relevant to cast a
separatrix between black hole (BH) and NS signatures as well as probe the
nuclear matter EoS and NS parameters from the Quasi-Periodic Oscillations
(QPOs) observed in Low Mass X-Ray Binaries.
