  We compare experimental spectra of radiative and semileptonic B decays with
the predictions of a model based on soft-gluon resummation to next-to-next-to
leading order and on a ghost-less time-like coupling. We find a good agreement
with photon spectra in the radiative decay and with hadron mass distributions
in the semileptonic one: the extracted values for alpha_S(m_Z) are in agreement
with the current PDG average within at most two standard deviations. The
agreement is instead less good for the electron spectra measured by BaBar and
Belle in semileptonic decays for small electron energies (< 2.2 GeV): our
spectrum is harder. We also show that, in general, the inclusion of
next-to-next-to-leading order effects is crucial for bringing the model closer
to the data and that the non-power expansion introduced in the framework of
analytic coupling studies does not accurately describe soft-gluon effects.
