  We present new Numerical Relativity calculations of the scattering angle
$\chi$ between two, equal-mass, black holes on hyperbolic-like orbits. We build
upon previous work considering, for the first time, spinning black holes, with
equal spins either aligned or antialigned with the orbital angular momentum. We
detail the numerical techniques used in the computation of $\chi$. Special care
is taken in estimating error uncertainties on the quantities computed. The
numerical values are compared with analytical predictions obtained using a new,
state-of-the-art, effective one body model valid on generic orbits that
incorporates post-Newtonian analytic information up to 5PN in the nonspinning,
conservative sector and that has been additionally informed by Numerical
Relativity simulations of quasi-circular coalescing black hole binaries. Our
results indicate that the spin sector of the analytic model should be improved
further in order to achieve satisfactory consistency with the most relativistic
spinning configurations.
